Sports-Related Brain Injury: Lessons from the NFL

H. Hunt Batjer, MD (right)
President, American Association of Neurological Surgeons
Lois C. A. and Darwin E. Smith Distinguished Chair in Neurological Surgery
UT Southwestern Neurosurgery Department
Dallas, TX

Shelly D. Timmons, MD, PhD (left)
Chair-elect, AANS/CNS Washington Committee
Past-chair, AANS/CNS Joint Section on Neurotrauma and Critical Care
Geisinger Medical Center
Danville, PA

Editor’s Note:  The movie “Concussion” — dramatizing the impact of sports-related head injury in the National Football League — will open in theaters on Christmas Day 2015.  The following provides important information about this subject.

Historical Perspective

The toll of recurrent traumatic brain injuries (TBI) has been gaining widespread attention in the media and the public discourse in America for the last decade. Three significant contemporaneous phenomena have contributed to this:

1. Multiple reports of long-term brain damage in professional athletes;
2. Headlines regarding concussion in young athletes as the Centers for Disease Control (CDC) revised their estimates upward to approximately 3.8 million sports-related concussions occurring per year in the U.S.; and
3. Returning soldiers from war exhibiting a distressingly high incidence of direct brain injuries, post-traumatic stress disorder (PTSD), or combinations. (The signs and symptoms of TBI and PTSD are strongly overlapping as are, of course, the events that cause them.)

Concern about football injuries (many resulting in death) was prominent in the early 1900s, leading President Theodore Roosevelt to issue the following charge to a group of academic leaders chaired by the Chancellor of New York University:

Do not report back to me until you have a game that is acceptable to the entire Nation. You must act in the public interest. This glorious sport must be freed from brutality and foul play.

This charge resulted in the formation of the National Collegiate Athletic Association (NCAA), organized primarily to protect collegiate football players from death, paralysis, and severe injury.

Fast-forward to 1968, when a rash of thirty-two athletic deaths led to the formation of the National Operating Committee for Standards in Athletic Equipment (NOCSAE).  NOCSAE developed a standard for football helmets that required survival of the helmet after an anvil drop. This led to the development of the shell helmet that exists today. This testing device has been successful at eliminating on-field device failure, skull fracture, subdural hematoma, and death. Whether this device protects against mild and moderate impacts such as concussive blows is unclear. In fact, it is conceivable that the shell helmet amplifies rather than dampens the effects of lower velocity impacts. More study on this critical topic is needed and is ongoing.

The long-term impact of repeated blows to the head and brain injury may manifest as chronic traumatic encephalopathy (CTE). The concept of chronic traumatic encephalopathy from sport is not new. This phenomenon was described decades ago by Harrison S. Martland, MD, a pathologist who published a seminal paper in JAMA in 1928, entitled “Punch Drunk.” In this manuscript, he described professional fighters and their trainers withstanding significant burdens of cranial trauma with clear neurological sequelae. Additionally, the phenomenon of “shell shock” in soldiers during World War I, or “combat stress reaction” in World War II, has long been recognized and likely consisted of elements of both traumatic brain injury and PTSD.

Neurosurgeons have long been involved in the diagnosis and care of individuals with sports-related injuries. They have also contributed significantly to clinical and basic science research on the subject, as well as to the public policy issues that have shaped current guidelines for evaluation and treatment. Given the magnitude of the issue and the impact on society, a Neurosurgery Blog series called “Hard Knocks,” has been developed to relate the current concepts.

Understanding CTE (Chronic Traumatic Encephalopathy)

Many American’s (not just football fanatics) were stunned by Junior Seau’s suicide in 2012. The subsequent publication in the lay press of the findings of CTE after his brain autopsy unleashed a media firestorm. The autopsy result heightened awareness about CTE but, unfortunately, it also has led to the promulgation of misinformation on the subject. Neurosurgeons are intimately involved in work related to CTE and want to help the public understand what we know and what remains yet to be learned about CTE and any correlation with concussions.

The frequency of publications on chronic traumatic encephalopathy has dramatically increased in the past twenty years, with greater public awareness and advancing biomedical knowledge and techniques. Media attention has been stoked by reports of autopsies in professional football players demonstrating CTE. Some media reports have suggested an extremely high incidence of CTE in relatively young former players.  Eventually, these predictions may be proven correct, but at present these anecdotal reports have yet to be confirmed through rigorous scientific testing. CTE is likely a real phenomenon, but the actual incidence and prevalence remains unknown due to a lack of data on the following:

• Data on large numbers of athletes or other individuals who have sustained repeated head blows that did not develop the pathological findings of CTE;
• Detailed data on the numbers of blows, the types of blows, or the immediate aftermath of injuries regarding objective neuropsychological, cognitive, or physical symptoms for many of those who did develop the findings of CTE; and
• Data concerning the impact of current concussion management and return to play protocols to identify if allowing the brain to recover fully after injury prevents long term effects.

What we do have are anecdotal reports of individual athletes who have exhibited neurocognitive decline, mood disorders, and neurobehavioral issues and some degree of correlation with histopathological findings of protein deposition in certain areas of the brain. However, these clinical patterns and pathological findings may be impacted by as yet undefined factors including:

• Genetics (with which there are known associations); and
• Environmental influences including diet, medication use, performance-enhancing or otherwise, and other factors.

It is very likely that a genetic allele called APOE e4, and other genetic susceptibilities causing problems with neuronal repair, contribute to individual vulnerability to this condition. It is also possible that the cumulative “dose” of impacts to the brain over a lifetime or career matter, perhaps more than the number of concussive blows.

Establishing CTE as an entity, along with the neuropathological findings, has been an important step forward in the arena of sports-related head injury. However, the bottom line is that we do not yet understand the factors that make one individual prone or resistant to the development of protein deposition, or explain in detail the link between the protein deposition and the clinical patterns of decline that have been sporadically reported. Many variables occurring over a lifetime may contribute.  Advanced research needs to be done with very carefully designed prospective databases and longitudinal studies over an extended period. Neurosurgeons embrace these types of studies and on an organizational level have worked collaboratively with many groups including the National Football League (NFL), National Hockey League (NHL), and many academic institutions to move this critical work forward.

Highlighting Promising Avenues of Research on CTE

Ongoing research into the pathophysiology, diagnosis, and treatment of CTE is a crucial component in the arena of sports-related head injury. Historical perspectives have previously been outlined, and a basic definition of what we currently know about CTE has been offered. New exciting avenues of research are the goal of this section.

• New Brain Imaging Techniques.  Since minor concussive blows result in no clear imaging signature on MRI or CT, some research efforts are focused on advanced imaging platforms to identify objective evidence of injury. One such method involves looking for the abnormal proteins (called tau ligands) on positron emission tomography (PET scanning). It is hoped that this technology will help pick up the earliest evidence of degenerative brain conditions.

• Autopsy Study of Brains.  A system has been established that facilitates the codified study of athletes’ brains after their death. This process was used when NFL athlete, Junior Seau, tragically died of suicide in 2012.  His brain was evaluated in such a manner at the National Institutes of Health (NIH), where neuropathologists examined it independently. Mr. Seau’s brain tissue was then sent to three different centers with samples from two other brains — including one from a person with Alzheimer’s Disease and one from a person who had suffered a non-traumatic death — for blinded comparisons. One-hundred percent of all neuropathologists who studied the tissue agreed that his brain had findings consistent with prior studies of people who had had repeated head trauma. Blinded independent verification of results is a helpful adjunct to study in this area.

• Understanding New Parameters.  One issue affecting outcomes in professional athletes after brain injury is physical stature. The professional athletes of today are not the same as their predecessors of decades past. They are bigger, faster, and stronger and their highly conditioned states — especially in a sport like football — may put players at increased risk than historical controls due to impact velocity. This must be taken into account with current practices aimed at protecting athletes as well as in longitudinal research studies. Attempts at objective quantification of mechanical impact are therefore critical.

• Measuring Acceleration Injury.  Understanding and mitigating physical impact in the sport of football are significant challenges. The capability of measuring these blows precisely — both from a linear and rotational basis — lends better understanding for helmet design and can provide tools to reinforce safer playing techniques — both of which can keep the players’ brains out of harm’s way. It is very likely that rotational acceleration is the physiological perturbation that creates the clinical constellation of events that we call concussion. Recent tests of the best commercially available accelerometers at two independent testing centers found that both devices did fairly well (with engineering-led optimization) in detecting impacts to the head, but not in quantifying rotational acceleration. Two devices were tested on the NFL field last year and got similar disappointing results in the detection of rotational acceleration impacts. Work in this area is ongoing.

• Defining Gender Differences.  The impact of gender on concussive injuries in athletes of all levels is likewise crucial. When one examines sports with the same rules played by men and women, women consistently have a higher incidence of concussive injuries than men. While this may be reporting bias based upon behavioral patterns that are different between genders, it may also be a result of physical characteristics. For example, the neck and shoulder girdle muscle mass has been shown to be different between men and women — particularly at the collegiate level. This may create vulnerability for women. Margot Putukian, MD, the director of Athletic Medicine at Princeton University, has devoted years of study to this field. She has noted that women may exhibit different playing styles and launch angles, which can put the head more at risk. Hormonal influences may also be at work.

• Youth Vulnerability Issues.  Youth athletes may be more vulnerable than collegiate or professional athletes due in part to the fact that the central nervous system myelinates incrementally over our first two decades of life. In addition to the importance of myelin in conducting electrical signals, there is also a school of thought that it acts as insulation or structural support aiding in the absorption of mechanical injury to the nervous system. In addition, children have less development of their cervical and shoulder musculature, larger head size relative to their bodies, and a higher probability of using poor playing techniques — all of which may increase their concussion risk. Unfortunately, in football, there is an erroneous belief that a helmet makes the child invulnerable to injury, leading to overconfidence and spearing. It must be continually taught that the helmet is a protective device and not a weapon. Most importantly, children carry a higher risk of second impact syndrome. This terrible condition can result in severe hyperemia and hemorrhage into the brain when a second concussion occurs before a prior injury has recovered. In 2006, Zachary Lystedt, a young football player in the state of Washington, had such a catastrophic injury and his story and advocacy efforts by his family led to the first youth protective law passed in the United States.

Neurosurgeons Leading the Way

In 2007, as public awareness of TBI, in general, was heightened, the New York Times posed an aggressive challenge to the NFL regarding its past policies related to concussive brain injuries. Congressional hearings began in 2009 that challenged the NFL’s current policies and acknowledged the enormous trickle-down phenomenon of any NFL policy and its impact on collegiate and youth sports.

After a national search by the NFL, in 2010, neurosurgeons Richard G. Ellenbogen, MD and H. Hunt Batjer, MD were appointed Co-Chairs of the NFL’s Head Neck and Spine Committee. After assuming these leadership roles, NFL Commissioner Roger Goodell charged them with achieving sports-related head injury protection legislation in all fifty states. To accomplish this, they went to Seattle and worked with retired U.S. Army General Peter W. Chiarelli, representatives of the CDC, and numerous people who had been instrumental in getting laws passed. The group also created training modules that Jeff Miller, senior vice president of health and safety policy at the NFL, was able to use to lobby states to pass legislation similar to the Lystedt Law. In an amazingly short period, such laws passed in all fifty states. The elements of these laws vary, but commonly included critical components are:

• Education of children and parents as to the signs and symptoms of brain injuries before the season;
• Immediate removal of a player from practice or play when any symptoms develop suggestive of concussion; and
• Return to play predicated on clearance by an independent practitioner.

Neurosurgeons are uniquely qualified to lead the efforts in protecting athletes and soldiers from brain injuries as well as management of those problems. As part of their core competencies, neurosurgeons manage all levels and severities of brain trauma from the earliest years of their training and throughout their practice lives. In recognition of this expertise, Drs. Ellenbogen and Batjer appointed three other neurosurgeons to lead subcommittees for the NFL, as well as individuals from other medical specialties that are heavily invested in brain injury management. Significant resource allocation has subsequently resulted in research into the biomechanics of sports-related concussive injury as well as prevention efforts.

Challenges in the NFL: Lessons Learned

There have been some challenges in trying to ensure that the sport of football is as safe as it can be without destroying the integrity of the game. Two early observations were clear and educational processes and rules changes were implemented based on these observations.

First, today’s great players are highly competitive and do not want to come out of any game at any time. This competitiveness is obviously a critical element of an iconic national sport, but herculean efforts have been made to temper that motivation with the idea that while athletes often play through physical pain, they should not play through brain injury. Doing so can put the players life and future in jeopardy.

Secondly, the “fog of battle,” that precludes seeing every player on every play can encumber the visualization by interested parties and physicians from the sidelines. Early on after the Committee was restructured, a chain of command was developed that allowed observed injuries to be transmitted to the physicians and trainers on the sideline who could mandate an evaluation of a player. Other rules changes have been implemented to allow better detection of injuries. The NFL Commissioner made a new rule in 2009 that any symptoms of concussive injuries required the player to be taken out of practice or a game with no same day return. Injured players had to be cleared by the team physician, as well as by an independent neurological consultant before they could return to play activities.

A few years later, a play occurred in which an official saw a player who almost certainly was concussed and did not notify the sidelines. Within days, officials were charged with a new responsibility to observe for injuries and notify the appropriate team physician if a concussion was observed. Additional layers of protection include:

• The master control booth at the NFL league office in New York was also given observers who had direct access to both benches; and
• An observer was placed in the replay booth at each stadium with a phone link to team physicians.

However, the following season an unfortunate play occurred in which a quarterback made a pass and was knocked unconscious by a defensive player. The observer in the booth saw this injury, stood up, and immediately saw the head physician running onto the field. Thinking that his duties had been accomplished, he turned his attention elsewhere. Unfortunately, the team physician was running to the aid of another player and did not see the quarterback down. By the time the quarterback was assessed, he was lucid and was complaining of pain in the arm, but attention was not given to his brain injury. As a result of this and other injuries, a certified athletic trainer (ATC) was placed in each replay booth. These trainers have access to eight to fifteen replay cameras and phone lines to both benches. Each physician has access to a high-definition video monitor at the sideline so that the medical teams can watch replays to evaluate the mechanism of an injury.

The Head Neck and Spine Committee works closely with the Competition Committee under Mr. Rich McKay. In 2011, a rule change was made in which the restraining line on kickoffs was moved from the 30- to the 35-yard line to increase the instances of touchbacks and reduce the instances of kickoff returns (plays with a higher rate of head injury). Also, the Madden rule was enacted in which a player with a diagnosis of concussion was mandated to return to the locker room and not stay on the sideline.

In spite of all of these rules changes, several significant misses by club medical staffs resulted in the decision to place unaffiliated neurotrauma consultants (UNC) on each bench for each game. Physicians (mainly, but not exclusively, neurosurgeons) were positioned at each NFL hub city to be coordinated with the emergency action plan for that stadium for the more critical injuries as frequently as possible. As a result of having this physician available, trust amongst players, team staff, and physicians has been enhanced, and decisions are now being made by consensus. The UNCs eliminated controversy, particularly on return-to-play decisions. Beginning with the 2014 season, the NFL implemented a requirement that the UNC must see any player who is being considered for a return to play decision.

NFL Working Hard to Protect its Athletes

As an independent and unpaid Committee, the members have been enormously impressed with the commitment of Commissioner Goodell, Mr. Jeff Pash, Mr. Jeff Miller, and many others at the NFL to make the game better and safer for those who play it. One such effort involves ongoing player education and training. In 2010, during week six, there were several alarming and illegal plays that occurred across the League. Drs. Ellenbogen and Batjer notified the League office, and two days later Mr. Ray Anderson, Vice President for Football Operations at the NFL, had a DVD delivered to each club. Every player was mandated to watch the DVD, in which Mr. Anderson articulated the rules, demonstrated plays that were illegal, and made it clear that players would be fined or suspended for illegal plays, even if the game officials did not flag the play.

The rules changes have had demonstrated results. For the first time, during the 2013 season, a significant decrease in the number of concussions diagnosed during the pre-season and regular season was noted. There was a reduction in helmet-to-helmet concussive injuries, but an increase in helmet-to-playing surface injuries — which has stimulated new research activity. The restraining line change on kickoffs had a dramatic impact on concussions during kickoffs in the NFL. Before that rule change in 2011, there were typically about 2,500 kickoff returns each year and with the new rule implementation, this number has dropped to 1,700. As a result, concussions on kickoffs decreased by 40-percent. The rule change has reduced the number of kickoff returns without substantially impacting the integrity of the game.

Neurosurgeons and NFL Reaching Out

The NFL is working in the broader context of health policy for sports and military personnel in many ways, including:

• Major projects have been undertaken involving the Department of Defense (DOD) and the NIH, and more recently with General Electric (GE) and Under Armour.
• Thirty million dollars were committed to the NIH Foundation to study Chronic Traumatic Encephalopathy, as well as to launch longitudinal studies to determine predictors of delayed neurological deterioration.
• The NFL also committed $30 million to the NFL/GE/Under Armour research challenge.  New platforms for detecting and evaluating concussive and sub-concussive blows have been identified as a major challenge, as has developing innovative approaches for preventing and diagnosing brain injuries in real time.
• The Head Neck and Spine Committee is working to develop better protective headgear and is collaborating more productively with NOCSAE by establishing a new sub-committee on mechanical engineering. Dr. Jeff Crandall will chair the new Engineering Subcommittee, and he has identified experts from all over the country to work closely with him to accomplish these goals.
• Collaboration with our international colleagues from sports across the world is being undertaken. Already, Australian rugby organizations, as well as English riding sports, the Federation International de Football Association (FIFA), and others have presented valuable data. An international research agenda to identify shared concerns from those discussions is being developed.

In summary, much is yet to be defined about the long-term effects of concussion in sports at all levels, and from repeated brain injuries in general.  Public awareness of traumatic brain injury has skyrocketed in the last decade, and with that comes many questions.  Importantly, role model organizations must take the lead in developing safer practices, safer equipment, educational offerings, rules refinement and enforcement, and objective research in this important area. Because of our education, training, and experience, neurosurgeons are uniquely poised to lead many of these efforts.

Editor’s Note:  This piece represents the start of a new blog feature called “Hard Knocks,” which will focus on neurosurgeons in the field of sports-related injury. Stay tuned for more valuable information.