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

Longitudinal alterations in cerebral perfusion following a season of adolescent contact sport participation compared to non-contact athletes

BACKGROUND

Cerebral blood flow (CBF) change, a non-invasive marker of head injury, has yet to be thoroughly investigated as a potential consequence of repetitive head impacts (RHI) via contact sport participation in youth athletes. We examined pre-to post-season differences in relative CBF (rCBF), arterial transit time (ATT), and neurocognition between adolescent contact sport (CS; 79.4% of which were football players) and non-contact sport (NCS) athletes.

METHODS

Adolescent athletes (N = 57; age = 14.70 ± 1.97) completed pre- and post-season clinical assessments and neuroimaging. Brain perfusion was evaluated using an advanced 3D pseudo-continuous ASL sequence with Hadamard encoded multiple post-labeling delays. Mixed-effect models tested group-by-time interactions for rCBF, ATT, and neurocognition.

RESULTS

A significant group-by-time interaction was observed for rCBF in a cluster consisting primarily of frontal and parietal lobe regions, with regional rCBF increasing in CS and decreasing among NCS athletes. No significant interaction was observed for ATT. A significant group-by-time interaction was observed for verbal memory and visual motor speed, with NCS athletes improving and CS athletes exhibiting lower performance from pre-to post-season in comparison.

CONCLUSIONS

Alterations in rCBF and variability in cognition, not purported neurovasculature changes (measured by ATT), were observed following one season of CS participation. Further study surrounding the clinical meaningfulness of these findings, as they related to adverse long-term outcomes, is needed.

Effects of Cumulative Head Impact Exposure in Adolescent Male Contact and Collision Sport Student Athletes

OBJECTIVE

This prospective cohort study aimed to investigate the association between head impact exposure (HIE) and neuropsychological sequelae in high school football and ice hockey players over 1 year.

SETTING

Community sample.

PARTICIPANTS

A cohort of 52 adolescent American football and ice hockey players were enrolled in the study, with a final study sample of 35 included in analyses.

DESIGN

The study followed a prospective cohort design, with participants undergoing neuropsychological screening and accelerometer-based measurement of HIE over 1 season.

MAIN MEASURES

Changes in cognition, emotions, behavior, and reported symptoms were assessed using standardized neuropsychological tests and self-reported questionnaires.

RESULTS

Cumulative HIE was not consistently associated with changes in cognition, emotions, behavior, or reported symptoms. However, it was linked to an isolated measure of processing speed, showing inconsistent results based on the type of HIE. History of previous concussion was associated with worsened verbal memory recognition (ImPACT Verbal Memory) but not on a more robust measure of verbal memory (California Verbal Learning Test [CVLT]). Reported attention-deficit/hyperactivity disorder history predicted improved neurocognitive change scores. No associations were found between reported history of anxiety/depression or headaches/migraines and neuropsychological change scores.

CONCLUSION

Overall, our findings do not support the hypothesis that greater HIE is associated with an increase in neuropsychological sequelae over time in adolescent football and ice hockey players. The results align with the existing literature, indicating that HIE over 1 season of youth sports is not consistently associated with significant neuropsychological changes. However, the study is limited by a small sample size, attrition over time, and the absence of performance validity testing for neurocognitive measures. Future studies with larger and more diverse samples, longer follow-up, and integration of advanced imaging and biomarkers are needed to comprehensively understand the relationship between HIE and neurobehavioral outcomes. Findings can inform guidelines for safe youth participation in contact sports while promoting the associated health and psychosocial benefits.

A systematic review on the risk of neurodegenerative diseases and neurocognitive disorders in professional and varsity athletes

Objective

The aim of this systematic review (SR) was to gather all available epidemiological evidence on former participation in any type of sport, at a professional and varsity level, as a potential risk factor for neurodegenerative diseases (NDs) and neurocognitive disorders (NCDs).

Design

Systematic searches were performed on PubMed, the Cochrane databases, and the ISI Web of Knowledge databases. Included studies were assessed using the NOS checklist.

Eligibility criteria for selecting studies

All epidemiological studies reporting data on the possible association between a clinical diagnosis of amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND), dementia or mild cognitive impairment (MCI), Parkinson’s disease (PD), chronic traumatic encephalopathy (CTE) at any stage and with any clinical pattern and the former participation in any types of sport at a varsity and professional level were included.

Results

Data from the 17 included studies showed a higher frequency of NDs and NCDs in former soccer and American football players. Updating the previous SR confirmed a higher frequency of ALS/MND in former soccer players. Data reported a significantly higher risk of dementia/AD in former soccer players, and of MCI in former American football players. Results also showed a significantly higher risk of PD in former soccer and American football players, and a significantly higher risk of CTE in former boxers and American football players.

Summary/conclusions

This SR confirmed a higher risk of NDs and NCDs in former professional/varsity athletes. However, the pathological mechanisms underlying this association remain unclear, and further high-quality studies should be performed to clarify whether the association could be sport specific.