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.


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.


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.


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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cte, dui, second opinions…3 dot

Saturday, September 23, 2017

Thoughts from the week. More three dot …

CTE may not be as chronic as the name implies. Changes of chronic traumatic encephalopathy were found in the brain of Aaron Hernandez, a former NFL player, who committed suicide while in jail after being convicted of murder…The disease, which can only be diagnosed by autopsy is thought to be a consequence of concussion. Tau proteins are deposited in the brain and eventually are thought to affect cognition, and cause mood swings and depression. The theory suggests that the NFL puts players at high risk because of repeated concussions, but with CTE found in brains of high school and college students, it may be that NFL players have a higher incidence of CTE because they are studied more frequently and that their brains were damaged at a much earlier age…Boston University researchers found that those who participated in youth football before the age of 12 had a twofold risk of problems with behavioral regulation, apathy and executive function and a threefold risk of clinically elevated depression scores. The average age of subjects was 51 and included high school, college and NFL players.

Viking quarterback Sam Bradford, he of two knee ACL reconstructions, developed knee swelling as the NFL season began and after missing another game, it has been reported that he has sought a second opinion regarding potential treatments (presumably surgery) from Dr. James Andrews, one of the country’s leading orthopedic experts…Some might wonder why the Viking team doctor isn’t good enough to treat a star player, but to Mr. Bradford’s credit, another opinion is never a bad decision. In medicine, there are always different ways of doing things and if there is time to consider options, the wise patient should seek those out…The second opinion opportunity isn’t limited to pro athletes, but available to almost all. When it comes to deciding about an operation, a surgeon should welcome the request for a second option, and then help arrange it, providing names of reputable colleagues to review records and examine the patient…It should raise a red flag when a surgeon refuses or appears insulted.

Attributed to either William Gladstone or Willian Penn, “Justice delayed is justice denied” was taken to hear by the British court system in convicting and sentencing Wayne Rooney in a drunk driving case this past week…After being arrested in the wee hours of September 1, the British international soccer star, pled guilty to the charges of driving drunk. On September 18, his driving privileges were revoked for 2 years and he was sentenced to 100 hours of unpaid work as part of a 12-month community service order. He could have been sentenced to 6-months prison for his first offence…British courts have been cracking down on this behavior in light of an average of 940 deaths a year in England and Wales…By comparison, 10,000 victims die every year in the US…And Wisconsin considers a first offence DUI as a misdemeanor and 448,000 drivers have at least one DUI.

Greg Olsen, Carolina Panthers tight end, broke his foot and required surgery to insert a screw into the 5th metatarsal. He knew that something was wrong as he walked off the field…  Cleveland Browns receiver, fell awkwardly and hurt his hand but it was a day later that the broken bones were confirmed…David Johnson of the Arizona Cardinals had a dislocated wrist but continued to play. Just three examples that just because you can walk on it or move it, doesn’t mean that it isn’t broken. All it means is that the muscles and tendons that are associated with the area are working just fine. Walking stops when a bone or joint is deformed and cannot tolerate any movement, cannot support the weight of the body or the muscle/tendon is torn and cannot move a joint.

And a couple definition reminders:

  • A break, fracture, crack all describe the same injury,
  • a stretched or torn tendon is called a strain
  • a stretched or torn ligament is called a sprain. By definition an ACL tear is a sprained knee.
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