Concussion, CTE and what we don’t know

Monday, May 14, 2018

What we wish we knew about concussion and CTE would make life easier for athletes, their parents, coaches and league administrators. It’s tough to remember that concussion research is in its infancy and the final answers about the way the brain reacts to injury, both in the short term and long term is still a mystery. Regardless of the headlines, there are many things we don’t understand. What should be common sense, may or may not be true.

Diagnosis

The only way to diagnosis chronic Traumatic Encephalopathy is after death, by autopsy, and using special techniques to look for abnormal proteins in brain tissue. Tau proteins are located in the brain and help stabilize microtubules inside brain cells called neurons. Abnormalities of an enzyme may cause tau proteins to fold abnormally and clump into “neurofibrillary tangles”. Other brains cells may also be affected.

While the diagnosis of CTE may be suspected because of symptoms like depression, suicidal thoughts, confusion, and short term memory loss, there is no test available for patients to confirm the diagnosis while they are alive.

The pathology findings under the microscope suggest that there is a difference between Alzheimer disease and CTE based on where the tau tangles occur and the presence of amyloid plaque (a sticky protein) seen in Alzheimer.

Concussion

The relationship between head injury and CTE seems to be well established. Using boxing research, it may be the number of hits to the head that make a difference as opposed to whether a concussion occurred. Studies suggest that “punch drunk syndrome” leading to dementia pugilistica found that it was the number of rounds boxed that was the important factor in determining long term brain issues, rather than the number of concussion.

This presumes that we know how to make the diagnosis of concussion and the answer is that we don’t. There is no test to confirm that a concussion has occurred. We know a concussion when we see it: a player who is temporarily confused or knocked unconscious, has a brief seizure or has an abnormal neurologic exam is an easy diagnosis. Many times, the symptoms of concussion may be delayed by hours and those symptoms may be subtle, involving sleep disturbance, ability to concentrate or minor changes in personality.

A concussion may be caused by a direct blow to the head, face or neck or it may be caused when a force to another part of the body is transmitted to the head. Imagine a car wreck where the seat belt holds the body in place but the head whips back and forth.

Not only can we not diagnosis a concussion with certainty, we also do not know when the brain has healed itself from injury and has returned to “normal”.

Cause and Effect

Making the link between head injury, concussion and CTE seems to have occurred, but the question there are plenty of questions left to answer. Does CTE risk increase with the number of concussions or does is it the age of the brain when that first concussion occurs?  Contact sports increase the risk of head injury and the prevalence of CTE in NFL players has led to lawsuits to care for players who develop debilitating symptoms after their careers have ended.

In soccer, recent research suggests that heading the ball affects brain function more than head injury caused by collision. This supports the concept that the number of minor hits may be as important or perhaps more important than a single concussion.

Newer recommendations from research have suggested that concussed brains that are not fully developed are at higher risk for future behavior problems and decreased executive thinking, including initiating activities, problem solving, and planning and organizing. The suggestion is that between the ages of 10 and 12, the brain is undergoing major growth and development and may be particularly vulnerable to injury. Recommendations suggest that tackle football should be avoided before age 12.

Implications

The NFL and NHL rightly are concerned about the long-term consequences of head injury to their players. Those who make it to the pro level have played more games at a higher level and presumably with more exposure to violence than those who didn’t make it to the college level and beyond. A case study published this year found that an 18-year-old high school football player with multiple concussions had, on autopsy, already developed abnormal tau protein tangles in his brain.It may be that the die has been cast for the pro…what happens in the major leagues may be inconsequential as to the development of abnormalities in the brain that are associated with CTE…or, it’s those concessions that occur because of collisions with larger and faster opponents may be the culprit.

The bottom line is that research teaches us much as to the consequences of head trauma and the potential for long term brain dysfunction. It also reminds us that we don’t know what we don’t know.

Protecting players at all levels of competition is a reasonable approach, but that risk of concussion will never be zero, and because of that the risk of CTE will never be zero. Asking the NFL, NHL, NCAA and high school leagues to alter the game maybe appropriate, but there is no way to know whether it will actually make a difference.

We can’t make the diagnosis of concussion. We can’t make the diagnosis of CTE. We don’t know how many concussions it takes to develop CTE and we don’t know if the brain has the ability to fix itself if it has been hurt.welcome to the world of science.

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concussion: looking out for those who are injured

Monday, November 13, 2017

As the NFL again takes flak this week for its head injury awareness with potential injuries to the Seahawks’ Russell Wilson, the Colts’ Jacoby Brissett and the Falcons’ Devonta Freeman, it’s important to remember that concussion symptoms can be subtle and have a delayed onset. The concept that a brief assessment on the sideline is sufficient to say yeah or nay on the diagnosis fails to meet the criteria set in the most recent consensus statemen from the 5th international conference on concussion in sport, held in Berlin in late 2016.

The bottom line for initial assessment is that all athletes, regardless on level of competition, should be removed from the field of play, if concussion is suspected. If the diagnosis is not in doubt, for example a player who is knocked out, briefly confused or has difficulty with balance, the player should not return to the game. If the diagnosis isn’t confirmed but suspicion exists, then the player needs to undergo sideline testing. But there is not one perfect test that can confirm or deny the diagnosis. Sideline screening can be done but it takes at least 10 minutes for most testing to be completed. While it can occur on the sideline, it is often better to find a quiet place to interview and examine the potentially injured player.

From the consensus guidelines:

“In cases where the physician may have been concerned about a possible concussion, but after the sideline assessment (including additional information from the athlete, the assessment itself and/or inspection of videotape of the incident) concussion is no longer suspected, then the physician can determine the disposition and timing of return to play for that athlete.”

And also from the same guidelines, an athlete with a sport related concussion should not be allowed to return to play on the day of injury.

There is a caveat that symptoms may be delayed and repeated evaluations are warranted. The problem is that the symptoms can be very subtle, from difficulty concentrating, to sleep disturbances, to changes in personality. The ability for the brain to function and process information may be affected so that concussed high school and college athletes may drop a full grade point in their classes for the ensuing semester.

As hard as it is to diagnose subtle head injury, it’s just as hard to decide when the brain has healed enough to allow the athlete to return to play. There is no test that confirms brain healing and most athletes recover within a month. Practically, return to play strategies take about a week if the athlete remains symptom free. That said, concussion symptoms may last for months.

Unfortunately for those who decide whether a Seahawk or Colt or Falcon can return to play, instant replay allows fans at home and in the stadium to witness the consequences of a hit to the head and judge for themselves whether the possibility of a concussion might exist. And when a referee sends a player off because of concussion concern, it’s incumbent upon the team’s medical staff to follow through with a thorough assessment. The player may not know what happened or realize that they were concussed; it’s up to the coaching and medical staff to protect the brain, even if the player actively refuses that help.

Until that is the standard of care, the NFL will continue to get flak.

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