Takeaway
Brain microstructural and functional changes occur in contact versus non-contact athletes during in- and off-seasons, even if they are clinically asymptomatic.
Why this matters
Although some studies report no cognitive effects in non-concussed contact-sport athletes, others suggest brain microstructural and functional changes are common in this population.
A proper understanding of this issue could impact current safety measures in contact sports such as rugby and the clinical monitoring protocols for these athletes.