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What We Know (and Don’t Know) About Football and Brain Injury

With the recent deaths of Ray Easterling and Junior Seau, and the prominence of head-shots within the Saints bounty scandal, football-related brain injuries have returned to the news.  Unfortunately for the general public, these reports don’t contain much useful information on the injuries and their causes, diagnoses, and treatments.  Over the past few weeks, I’ve had the opportunity to listen  and speak to Dr. Stefan Duma of Virginia Tech and Dr. Jeffrey Barth of the University of Virginia, both of whom are leaders in the field of head injury research.  Duma leads the most sophisticated head injury research facility in the country, and also leads the program that monitors head impacts received by VT players during games and practices.  Barth is a member of the NFL Players Association Concussion Committee and co-wrote a study that first put concussions in the public spotlight back in the 80’s.

Comparison of healthy brain tissue to that of a football player and a boxer; slide courtesy J. Barth..

Though the media is focused on repeated blows to the head (and reasonably so), it’s important to note that a single concussion can be extremely harmful.   A concussion is an injury to the brain caused by sudden acceleration.  A common technical term for a concussion is “mild traumatic brain injury,” which highlights its potential seriousness.  Athletes in many sports often play through mild concussions; Dr. Duma showed one clip of a former Virginia Tech linebacker who suffered a concussion during a play, stayed on the field, and nearly started the next play lined-up at deep safety before a teammate redirected him back to the box.  This was in the early days of the program when guidelines were still being established; a player at VT (and other schools with helmet-safety programs) in this situation today wouldn’t return to the field.

Concussions can cause disorientation, nausea, head pain, light sensitivity, unconsciousness, insomnia, mood changes, and memory loss.  The acute effects of a concussion last on average between 5 and 10 days.  Longer-term symptoms generally clear within three months, though extreme examples can last for years.  Children generally take longer to recover.  The typical concussion occurs when the head experiences around 100 g-force of acceleration (or 100 times the acceleration of earth’s gravity).  As a comparison, an amateur boxer’s dominant-hand hook can create about 80 g of head acceleration.

An average player at Virginia Tech will have four incidents of  circa-100 g head acceleration every season.  Interestingly, out of the entire team only about four actual concussions are diagnosed annually, while the rest of VT athletics reports around 26 concussions during the same period.  This speaks to the variability of concussion susceptibility, and also to football players’ ability to tense their bodies in ways that dampen impact forces.  Additionally, Duma notes that his research has lead to VT and other schools to adopt safer helmets and reduce or eliminate drills that lead to excessive head impacts.  Barth noted that rather than follow his committee’s recommended practice guidelines (which would reduce helmeted practices by roughly three-fourths), the NFL ownership installed rules that halved helmeted practices.

Concussions occur because both the head and the brain are each flexibly tethered, and both can independently whip about on impact, causing the sudden acceleration and deceleration responsible for concussions.  We know this movement can actually rip apart the connective links of brain cells, though beyond that we’re less certain about what else happens within the brain during and after a concussion.  We do know that having one concussion increases your risk of having another by 3-to-6 times, though we aren’t sure if this means certain people are simply prone to concussions, or if having one concussion increases your sensitivity to future brain trauma.  This increased risk is especially important to know because having a second concussion (even a minor one) during the acute phase of a prior trauma can lead to serious complications.  The only proven form of concussion recovery is rest and time.

Getting more into the controversy of football and head injuries, we don’t know how to define or quantify the effects of repeated concussions or repeated sub-concussion blows to the head.  It seems that repeated blows can trigger chronic traumatic encephalopathy (CTE), which is a condition that causes both brain deterioration and the harmful accumulation of defective tau protein in the brain.  Symptoms of CTE include chronic and worsening dementia-like memory and cognition loss, as well as depression, aggression, loss of motor control, and disorientation/confusion.  The symptoms generally appear late in a player’s life, though tau deposits are now being found in the brains of middle-aged men, active NFL players, and even teenagers who’ve had multiple concussions.  Over a dozen former NFL/college players have been diagnosed, and if media reports are to be believed, Easterling and Seau both displayed behavioral symptoms consistent with CTE.  Compared to the entire league, this is still a very small sample, which makes it difficult to determine just how frequently CTE occurs.

At the moment, CTE can only be diagnosed by post-mortem examination of the brain.  The Boston Center for the Study of Traumatic Encephalopathy that’s frequently referenced in media reports is among the best known institutions performing these examinations, and has done so on the brains of several NFL players.  Dr. Barth notes that Siemens’ healthcare division claims to be 18 months away from deploying PET scan technology capable of detecting CTE in living patients; while PET equipment isn’t nearly as common in hospitals as MRI and CT equipment, it’s a step in the right direction.

Our limited understanding of the brain and impacts is very cloudy.  It may turn out that only a small, definable subset of the 5 million adults, teens, and children currently playing football will ever be at risk for severe and/or long-term brain injury.  Or it may turn out we’re experiencing a sport-related epidemic of lasting brain injury.  We just don’t know.  In this situation, knee-jerk fears can give rise to sham treatments and unwise practices, while apathy can dampen efforts to learn more and create healthier practices.  As Dr. Barth consistently reinforces, we need to be comfortable with the ambiguity of this subject while working towards resolving it.

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