Subconcussive Head Impacts and Neurocognitive Function Over 3 Seasons of Youth Football

Effects of repetitive subconcussive head trauma on the neuropsychological functioning and symptom reporting of high school athletes in high and low contact sports: Age and sex

OBJECTIVE

The present study was designed to assess the neuropsychological test performances of non-concussed female and male high school athletes of different ages in high and low contact sports.

METHOD

Large samples of 2,510 high school athletes in High Contact sports (e.g., football) and 1,437 in Low Contact sports (e.g., basketball) were examined. The participants were administered a baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) prior to their respective seasons.

RESULTS

Multivariate linear regression showed that the High Contact athletes had significantly poorer results than the Low Contact athletes in all four ImPACT Composite scores and the Total Symptom scores. No age differences were found, but in all three age groups, the High Contact athletes had lower Visual Motor Speed scores than the Low Contact athletes. No test score differences were noted between the females in the High and Low Contact groups, but the High Contact males had poorer Visual Motor Speed and Reaction Time than the Low Contact males.

CONCLUSIONS

The present results were consistent with prior studies of subconcussive head trauma, with High Contact athletes obtaining overall poorer neuropsychological test results than Low Contact athletes. More investigations in this age group seems is warranted.

Head acceleration event exposure and cognitive and functional outcomes: a comparison of multiple football seasons

Athletes in contact sports are exposed to repetitive impacts as an inherent part of sport. There is concern over the accumulative effect; however, much is still unknown regarding their short-term effects. This study investigated impact accumulation and outcomes over three seasons (2015, 2017, 2019) in NCAA Football Bowl Subdivision players. Impacts were recorded using helmet accelerometers, and virtual reality testing (VR) was done across the season. Incidence rates for impacts (total; ≥25 G to <80 G; ≥80 G) all significantly differed by season (p < 0.05). VR scores changed across the seasons, specifically significant decreases in spatial memory (p < 0.05) in 2015, significant changes in balance and spatial memory (p < 0.05) in 2017, and no significant changes in 2019. Linear regressions predicting VR change score by impact incidence rate were nonsignificant. Monitoring exposure to impacts and changes in outcomes is useful; however, results are fluid, and many factors could indirectly have protective effects on athletes.

Use of functional near-infrared spectroscopy to quantify neurophysiological deficits after repetitive head impacts in adolescent athletes

There is concern that repetitive head impact exposure (RHIE) may lead to neurophysiological deficits in adolescents. Twelve high school varsity soccer players (5 female) completed the King-Devick (K-D) and complex tandem gait (CTG) assessments pre- and post-season while wearing a functional near-infrared spectroscopy (fNIRS) sensor. The average head impact load (AHIL) for each athlete-season was determined via a standardised protocol of video-verification of headband-based head impact sensor data. Linear mixed effect models were used to determine the effects of AHIL and task condition (3 K-D cards or 4 CTG conditions) on the change in mean prefrontal cortical activation measured by fNIRS, and performance on K-D and CTG, from pre- to post-season. Although there was no difference in the pre- to post-season change in K-D or CTG performance, greater AHIL was associated with greater cortical activation at post-season in comparison to pre-season during the most challenging conditions of K-D (p = 0.003) and CTG (p = 0.02), suggesting that greater RHIE necessitates increased cortical activation to complete the more challenging aspects of these assessments at the same level of performance. These results describe the effect of RHIE on neurofunction and suggest the need for further study of the time course of these effects.

Exposure to Head Impacts and Cognitive and Behavioral Outcomes in Youth Tackle Football Players Across 4 Seasons

IMPORTANCE

Repetitive head impacts have been posited to contribute to neurocognitive and behavioral difficulties in contact sport athletes.

OBJECTIVE

To identify associations between cognitive and behavioral outcomes and head impacts measured in youth tackle football players over 4 seasons of play.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study was conducted from July 2016 through January 2020, spanning 4 football seasons. The setting was a youth tackle football program and outpatient medical clinic. Players were recruited from 4 football teams composed of fifth and sixth graders, and all interested players who volunteered to participate were enrolled. Data analysis was performed from March 2020 to June 2021.

EXPOSURES

Impacts were measured using helmet-based sensors during practices and games throughout 4 consecutive seasons of play. Impacts were summed to yield cumulative head impact gravitational force equivalents per season.

MAIN OUTCOMES AND MEASURES

Ten cognitive and behavioral measures were completed before and after each football season.

RESULTS

There were 70 male participants aged 9 to 12 years (mean [SD] age, 10.6 [0.64] years), with 18 completing all 4 years of the study. At the post-season 1 time point, higher cumulative impacts were associated with lower self-reported symptom burden (β = -0.6; 95% CI, -1.0 to -0.2; P = .004). After correcting for multiple comparisons, no other associations were found between impacts and outcome measures. At multiple times throughout the study, premorbid attention-deficit/hyperactivity disorder, anxiety, and depression were associated with worse cognitive or behavioral scores, whereas a premorbid headache disorder or history of concussion was less often associated with outcomes.

CONCLUSIONS AND RELEVANCE

In this cohort of youth tackle football players, premorbid conditions, including attention-deficit/hyperactivity disorder, anxiety, and depression, were associated with cognitive and behavioral outcomes more often than cumulative impact.