by Robert Cantu, MD
Chronic traumatic encephalopathy is a progressive, degenerative brain disease caused by repeated head impacts, such as those suffered by boxers and football players.
In the later stages, it affects memory, judgment, mood and control of behavior.
Many people are familiar with famous football players like Ken Stabler and Aaron Hernandez who suffered from chronic traumatic encephalopathy (CTE). We now know that the disease likely has its foundation early in life, but there are several things that parents, coaches and primary care providers (including optometrists) can do to help reduce the risk of young players developing CTE in the future.
Avoiding concussions is a first step in helping reduce risk. There has been increasing focus in recent years on concussions in youth sports, with measures such as better helmets, “heads up” tackling and protocols that require removal from play after a concussion.
These are very positive developments, but it is also important to keep in mind that CTE is more closely associated with cumulative, subconcussive head trauma, so we can’t only be concerned about concussions.
Flag football for younger children
That’s why the Concussion Legacy Foundation recommends that kids start out with flag football and delay tackle football until age 14 or the start of high school.
Currently, the best evidence suggests a football player’s risk of CTE is primarily determined by the number of years they play tackle football and the age at which they start. Researchers have found that for every year younger an athlete begins to play tackle football, he could experience symptoms associated with CTE 2.5 years earlier. Multiple peer-reviewed publications have shown that deferring the start of tackle football is safer (Alosco et al., Stamm et al.). Although age 14 is somewhat arbitrary, there are both practical and scientific reasons to wait until high school.
Wait until high school for tackle football
Starting tackle football in high school still gives young athletes the opportunity to compete at a high level in a sport they love, but it reduces the number of years they sustain repeated subconcussive hits to the head, which should significantly reduce their risk of developing CTE.
Waiting until the athletes are older reduces head trauma during a period of intense brain development. The development of myelin, which protects nerve cell axons, peaks at around age 12. Important brain structures, including those controlling memory and emotion, reach their peak size between ages 8 and 12 years, and blood flow to the cerebrum peaks between ages 10 and 12 years.
Delaying tackle football until high school gives young people a chance to mature physically. Young kids can’t run as fast as older teens and they are lighter in weight, so one might assume that the hits they sustain won’t be as hard. However, younger players actually have heavier heads relative to their body size and much weaker necks than adults or older teens, which makes the neck less effective as a shock absorber. Using helmet sensors, researchers discovered that a youth player experiences head impacts rivaling those of college football players (Daniel et al.).
Finally, it is also important to increase awareness among primary care providers about the signs of brain injury in kids so that they can be appropriately treated. Here, optometrists have a real advantage.
Optometrists who see healthy kids for annual vision exams are in a unique position to help identify those at higher risk for future problems stemming from undiagnosed concussions or subconcussive injury. About 50% of the brain’s circuitry involves the visual system, so it stands to reason that visual dysfunction is a very important sign of brain injury.
A diffuse injury like concussion often causes problems with eye tracking, accommodation and light sensitivity, for example. These are subtle findings that other primary care providers who aren’t trained specifically in vision would likely miss.
With a few simple manual tests, optometrists can test convergence, saccades and smooth pursuits as part of their regular exams. If a child struggles with any of these tests, or the tests produce headache, lightheadedness, nausea or dizziness, it may be worth a referral to a neuro-optometric rehabilitation specialist or other concussion specialist who can perform a more in-depth evaluation. It could literally be a life-saving decision.
Alosco ML, et al. Ann Neurol. 2018;doi:10.1002/ana.25245.
Daniel RW, et al. Biomed Sci Instrum. 2014;50:291-296.
Stamm JM, et al. Neurology. 2015;doi:10.1212/WNL.0000000000001358.
For more information:
Robert Cantu, MD, is clinical professor of neurology and neurosurgery and co-founder of the CTE Center at the Boston University School of Medicine. He is senior advisor to the NFL Head, Neck and Spine Committee, co-founder and medical director of the Concussion Legacy Foundation and medical director of the National Center for Catastrophic Sports Injury Research at the University of North Carolina, Chapel Hill. He is a widely published and nationally recognized advocate for safety in youth sports.
Disclosures: Cantu reports he is senior advisor to the NFL Head Neck and Spine Committee, vice president and chair of the scientific advisory committee of the National Operating Committee on Standards for Athletic Equipment, and co-founder and medical director of the Concussion Legacy Foundation, receives royalties from Houghton Mifflin Harcourt and provides legal expert opinion for groups such as the National Collegiate Athletic Association and the National Hockey League.
For more information on the scientific evidence around CTE and the Concussion Legacy Foundation’s recommendations regarding youth football, visit https://concussionfoundation.org/sites/default/files/Documents/Flag_Under_14_White_Paper.pdf. For a directory of neuro-optometric rehabilitation specialists, visit www.noravisionrehab.org.
Disclaimer: The views and opinions expressed in this blog are those of the authors and do not necessarily reflect the official policy or position of the Neuro-Optometric Rehabilitation Association unless otherwise noted. This blog is for informational purposes only and is not a substitute for the professional medical advice of a physician. NORA does not recommend or endorse any specific tests, physicians, products or procedures. For more on our website and online content, click here.