But acute symptom severity may be linked to worse short-term outcomes

Length of exposure to football from childhood had no effect on short-term recovery measures after concussion, a study of NCAA football players found.

In adjusted models, estimated age of first exposure (eAFE) to tackle football was not associated with the number of days until asymptomatic, reported Thomas Buckley, EdD, of the University of Delaware and coauthors in Neurology. Estimated age of first exposure was defined as participant’s age at the time of collegiate concussion assessment minus self-reported number of years playing football.

“Earlier estimated age of first exposure to American football was not associated with longer symptom recovery, worse balance, worse cognitive performance, or worse psychological distress following concussion,” Buckley and colleagues wrote. “In these National Collegiate Athletic Association football players, longer duration of exposure to football during childhood and adolescence appears to be unrelated to clinical recovery following concussion.

“Greater acute symptom severity (i.e., symptom severity reported <6h following sport-related concussion) may be associated with worse clinical concussion outcomes 24-48 hours following sport-related concussion,” they added.

Outcome measures of the study included:

  • Days until asymptomatic
  • Cognitive measures, assessed by Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) composite of verbal memory, visual memory, visual motor speed, and reaction time, and the post-concussion symptom scale
  • Balance, assessed by Balance Error Scoring System (BESS) total score
  • Distress, measured by Brief Symptom Inventory 18 (BSI-18) sub-scores for somatization, depression, and anxiety; a global severity index suggests overall distress level

In unadjusted models, younger eAFE was associated with lower (worse) ImPACT visual motor speed scores (R2=0.031, P=0.012) at 24-48 hours following injury and lower (better) BSI-18 somatization sub-scores (R2=0.014, P=0.038) once athletes were asymptomatic.

“Younger age of first exposure to football was associated with worse visual motor speed acutely post-concussion and better psychological health following symptom resolution, but the effect sizes were small and did not persist after adjustment for multiple comparisons,” noted Robert Lynall, PhD, of the University of Georgia in Athens, and Kevin Barrett, MD, of the Mayo Clinic in Jacksonville, Florida, in an accompanying editorial.

“This study does not inform potential long-term detriments from early football exposure, but these results are important for clinicians dealing with acute concussion cases,” they wrote.

Exposure to American football begins as early as age 5, coincident with critical periods of neurodevelopment.

Age of exposure may be considered with respect to both long- and short-term outcomes. Prior research on long-term outcomes includes a 2015 study of 42 professional players ages 40-69 which found that age of first exposure of less than 12 was associated with worse outcomes on multiple cognitive tasks. A subsequent study in a cohort including 214 former amateur and professional players again found that first exposure before age 12 was associated with impairment of self-reported symptoms and executive function. A 2018 study of 86 symptomatic former professional football players found decreased thalamic volumes in those with more years of playing and with earlier age of first exposure, with the effect of age of first exposure about twice as strong as years of play.

Short-term outcome was previously evaluated by many authors of the present study in a 2020 report on age of first exposure to contact sport in U.S. service academy cadets. The study considered lacrosse, wrestling, ice hockey, soccer, and rugby in comparison with non-contact sports and concluded, “We observed no association between eAFE, contact sport participation, neurocognitive functioning, or subjectively experienced symptoms in this cohort.”

In the current study, Buckley and co-authors studied male NCAA football players who had assessments completed pre-concussion and within 6 hours of injury. Participants sustained a medically diagnosed concussion between baseline testing and post-concussion assessments. A total of 294 players were evaluated 24-48 hours following concussion and 327 were evaluated at the time they were asymptomatic.

Recruitment was part of the National Collegiate Athletic Association–Department of Defense Concussion Assessment, Research and Education (CARE) Consortium. For athletes who had multiple concussions throughout their CARE Consortium participation, only their first concussion was included in the study.

Athletes were about 19 years old. Average age of first football exposure was 10, and about 46% had a prior history of concussion.

“Notably, 73% of concussion diagnoses occurred in the practice/training setting, which serves as a reminder not to solely focus research and safety initiatives on the competition environment,” the editorialists pointed out.

Limitations of the study include evaluation of college athletes only by self-report. The assessment instruments may lack sensitivity to detect deficits that could reduce concussion recovery or long-term brain health.

“Future studies should incorporate advanced techniques such as imaging, blood biomarkers, and more rigorous neuropsychological batteries to further explore how age of first exposure to football may influence short- and long-term post-concussion management,” the editorialists noted.

  1. Length of exposure to football from childhood had no effect on short-term recovery measures after concussion, a study of NCAA football players found.

  2. This study does not inform potential long-term detriments from early football exposure, but results are important for clinicians dealing with acute concussion cases, the editorialists noted.

Paul Smyth, MD, Contributing Writer, BreakingMED™

The study was made possible, in part, with support from the Grand Alliance CARE Consortium, funded by the NCAA and the Department of Defense.

Buckley reported support from the Grand Alliance CARE Consortium and additional support from NIH/NINDS.

The editorialists reported no disclosures.

Cat ID: 130

Topic ID: 82,130,730,130,474,192,925