Exploring the effect of repeated rugby-related head injuries on brain health. Zimmerman et al

It is important to evaluate the long-term effects on brain health of repeated sports-related mild traumatic brain injuries (e.g. diffuse axonal or vascular injuries). This is particularly important for rugby players who have been exposed to these types of head injuries throughout their professional career. These injuries could lead to neurodegenerative diseases such as chronic traumatic encephalopathy, which has previously been reported in a small number of retired rugby players.^1–3 This led Zimmerman and colleagues to evaluate whether rugby participation and related head injuries are sufficient to lead to long-term brain injury.⁴ They investigated the relationship between rugby exposure and sub-acute head injuries using advanced magnetic resonance imaging (MRI). White matter structure, evidence of axonal and diffuse vascular injury, and changes in brain structure over time were assessed.

Of 44 studied adult elite rugby players, 10 (23%) showed imaging evidence of axonal or diffuse vascular injury. Abnormalities in fractional anisotropy, an indicator of white matter integrity following brain injury, were also observed. In contrast, the control group (non-collision-sport athletes) did not show any abnormalities. A longitudinal examination also revealed an unexpected reduction in brain volume in 50% of the studied rugby players, indicating potential neurodegeneration in white matter tracts. Cognitive performance, however, did not correlate with the observed white matter abnormalities. The authors conclude that an association exists between elite rugby participation and changes in brain structure; however, further longitudinal imaging research in both active and retired rugby players is needed to gain a better understanding of the impact of head injuries on brain structure and the potential for neurodegenerative disease in later years.

References

1. Buckland ME et al. Chronic traumatic encephalopathy in two former Australian National Rugby League players. Acta Neuropathol Commun 2019;7:97.
2. Stewart W et al. Chronic traumatic encephalopathy: A potential late and under recognized consequence of rugby union? QJM 2016;109:11–15.
3. Lee EB et al. Chronic traumatic encephalopathy is a common comorbidity, but less frequent primary dementia in former soccer and rugby players. Acta Neuropathol 2019;138:389–99.
4. Zimmerman KA et al. White matter abnormalities in active elite adult rugby players. Brain Communications 2021;3:fcab133.