Repetitive head impacts among professional fighters: a pilot study evaluating Traumatic Encephalopathy Syndrome and postural balance

ABSTRACT

Objectives

Clinical criteria for Traumatic Encephalopathy Syndrome (ccTES) were developed for research purposes to reflect the clinical symptoms of Chronic Traumatic Encephalopathy (CTE). The aims of this study were to 1) determine whether there was an association between the research diagnosis of TES and impaired postural balance among retired professional fighters, and 2) determine repetitive head impacts (RHI) exposure thresholds among both TES positive and TES negative groups in retired professional fighters when evaluating for balance impairment.

Methods

This was a pilot study evaluating postural balance among participants of the Professional Athletes Brain Health Study (PABHS). Among the cohort, 57 retired professional fighters met the criteria for inclusion in this study. A generalized linear model with generalized estimating equations was used to compare various balance measures longitudinally between fighters with and without TES.

Results

A significant association was observed between a TES diagnosis and worsening performance on double-leg balance assessments when stratifying by RHI exposure thresholds. Additionally, elevated exposure to RHI was significantly associated with increased odds of developing TES; The odds for TES diagnosis were 563% (95% CI = 113, 1963; p-value = 0.0011) greater among athletes with 32 or more professional fights compared to athletes with less than 32 fights when stratifying by balance measures. Likewise, the odds for TES diagnosis were 43% (95% CI = 10, 102; p-value = 0.0439) greater with worsening double leg stance balance in athletes exposed to 32 or more fights.

Conclusion

This pilot study provides preliminary evidence of a relationship between declining postural balance and a TES diagnosis among retired professional fighters with elevated RHI exposure. Further research exploring more complex assessments such as the Functional Gait Assessment may be of benefit to improve clinical understanding of the relationship between TES, RHI, and balance.

KEYWORDS:

• Postural balance
• concussion
• neurotrauma
• repetitive head impacts
• sport

Acknowledgements

We would like to thank the PABHS research team at the Lou Ruvo Center for Brain Health in Las Vegas for their tremendous work on this cohort. Equally, thank you to all the athletes who have volunteered their time to understand the long-term effects of repetitive head trauma.

Disclosure statement

No potential conflict of interest was reported by the author(s)

Authors’ contributions

BCK and LCC contributed to study design, data management, statistical analysis, and manuscript composition. CB contributed to the study design, data collection, and manuscript composition. CLC, BL, and DLY contributed to the study design and editing of the manuscript.

Competing interests

CB has received research funding from the UFC, Top Rank Promotions, Haymon Boxing, and Bellator Promotions. The other authors have no competing interests to report.

Data availability statement

The datasets generated during and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.