Friday, June 21, 2019

Smart Safety: Concussions and Sports, Part 2 - The Three Concussion Rule

LA-area Jeff Victoroff, M.D. is a Harvard trained neurologist who directed USC's Traumatic Brain Injury/Neuropsychiatry Clinic at Rancho Los Amigos National Rehabilitation Center for more than a decade, is also an award-winning teacher of neurology and one of the five neurologists recruited by former U.S. Surgeon General David Satcher to provide care for concussed, demented, former NFL players.

This is a continuation of our interview from a previous post.

Why do people go by the "three concussion rule" and why is it wrong?
First: The three concussion rule has absolutely no basis in any medical or scientific study published in the last 2000 years. It seems to have been invented by coaches to trick parents and players. You will never find a single mention of it in the more than 10,000 peer-reviewed publications on concussive brain injury.

Second: Please consider the practical problems with implementing such a rule:

Multiple research studies have shown that young athletes at every level of play tend to deny their brain symptoms after a hit. In addition, players routinely underreport their season and lifetime total dings and knockouts on interviews and surveys. 

For example, Register-Mahalik et al. (2013) found among high school athletes that "Only 40% of concussion events and 13% of bell-ringer recalled events in the sample were disclosed after possible concussive injury" (p. 645). 

And failed self-report of minor injuries is a special problem. As Kay et al. (2015) put it:

One significant issue with identifying concussions is that a clinical diagnosis is based on the presence of signs and symptoms, which are self-reported by the patient. In the adolescent population, injury to the brain is possible with even the slightest insult, which can affect recovery and predispose them to subsequent concussions (emphasis added; p. 210).
At present, when a child takes a hit, his or her brain damage cannot be assessed--not by interview, not by physical examination, not by blood tests, not be neuroimaging. Hence, it is literally impossible for a doctor to say what happened to our child's brain.

  • Where in the brain is that damage?
  • How were the child's neurons, axons, glia, synapses, and blood vessels impacted?
  • Did any neurons die?
  • Will that head impact trigger a lifelong process of brain inflammation?
Even if we put accelerometers into every child's helmet, it would tell us nothing about brain damage. As Broglio et al. (2011) and other scholars have admonished: "There appears to be no association between head impact biomechanics and post-concussive symptoms."

So, if athletes only report 13% of their symptomatic concussive brain injuries (not to mention the giant hidden problem of their asymptomatic injuries) and doctors have no way to diagnose them, how on Earth are we going to count to three accurately?

Third: It is absurd to claim that a certain number of observed head impacts or confessions of dizziness defines the right time to quit because of human individuality (O'Connor et al., 2017). No two children ever had the same brain changes after identical hits! Dozens of variables affect the risk of a given hit in that one individual, including his or her genes, epigenetic changes, pre-injury emotions; fatigue, state of hydration that day,....and in girls and young women, their time of the month can make the difference between less damage and more (Wunderle et al., 2014).

Bottom line: your daughter could get three concussions and win the Nobel Prize. My daughter could get three concussions and end up in a coma. The number of so-called concussions that we know about does not matter! It's the brain damage that matters--and we have no way to measure it.

Jeff Victoroff, M.D. is a Harvard trained, board certified neurologist and psychiatrist, also certified in Behavioral Neurology and Neuropsychiatry. He serves as Associate Professor of Clinical Neurology and Psychiatry at the Keck School of Medicine of the University of Southern California (USC). He directed USC's Traumatic Brain Injury/Neuropsychiatry Clinic at Rancho Los Amigos National Rehabilitation Center for more than a decade. He is an award-winning teacher of neurology and the recipient of an award from the Brain Injury Association of America. He was one of the five neurologists recruited by former U.S. Surgeon General David Satcher to provide care for concussed, demented, former NFL players. His new book, Concussion and Traumatic Encephalopathy: Causes, Diagnosis and Management, is available on Amazon and other fine booksellers.

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