Sport-related concussion: How best to help young athletes

What to tell athletes—and parents—about repetitive head trauma

There is growing concern about the long-term risks of concussion and repetitive head impact that may manifest as chronic traumatic encephalopathy (CTE) and chronic neurocognitive impairment (CNI) later in life. Indeed, some data strongly suggest—but do not definitively prove—a relationship between repetitive head injury and chronic neurodegenerative disease.^8-10 You can tell worried patients or parents, however, that the majority of research on CTE and CNI has been based on professional football players.

Studies of long-term effects of soccer heading have shown conflicting results, with some finding cognitive impairment, altered postural control, and anatomic changes of the brain, while others found no effect on encephalopathy, concussion symptoms, or neurocognitive performance.^29-36Here, too, most studies showing negative effects of soccer heading involved professional athletes.

Repetitive sub-concussive impact in high school football athletes has been found to induce biochemical changes to the brain,³⁷ but the long-term effects are unknown. And, while concussion in high school athletes has been associated with short-term cognitive impairment, altered neurochemistry, and evidence of increased symptoms on baseline neurocognitive testing,^8-10,38 no studies have linked concussion during middle school or high school with CNI. What’s more, a long-term (50-year) follow-up study of individuals who played football in high school found no difference in rates of neurodegenerative disease compared with age-matched controls.³⁹

A 50-year follow-up study of individuals who played football in high school found no difference in rates of neurodegenerative disease when compared with age-matched controls.

A new study of high school and college football players (mean age: 17.4 years) presented at the American Academy of Neurology 2016 Sports Concussion Conference in Chicago in July, however, found significant alterations in white matter 6 months post injury.⁴⁰ The researchers compared 17 athletes with sport-related concussion with matched controls, using diffusion tensor imaging and diffusion kurtosis tensor imaging as biomarkers of brain recovery. The concussed athletes underwent MRI and symptom assessment at 24 hours, 8 days, and 6 months. The controls followed identical protocols.

At the 6-month assessment, there were no differences between the concussed group and the controls in terms of self-reported concussion symptoms, cognition, or balance. However, the concussed athletes had widespread decreased mean diffusivity compared with the controls. Despite the lack of clinical symptoms, the concussed athletes showed significant alterations in white matter “that were related to initial symptom severity ratings,” the authors concluded. These findings have implications both for determination of recovery from concussion and concussion management, they added.⁴⁰

Although there is no way to eliminate all concussions, limited evidence suggests that improving athletic technique, limiting contact at practices, better enforcement of game rules, and rule changes regarding physical contact may decrease concussion risk.^41-43 Many youth sports organizations have developed policies placing restrictions on head impact during practices and games. Studies are ongoing, too, to see if better headgear—or requiring helmets for soccer players—makes a difference.

CORRESPONDENCE
Ryan A. Sprouse, MD, CAQSM, 203 East Fourth Avenue, Ranson, WV 25438; rsprouse@wvumedicine.org.