A number of former rugby union players are suing governing bodies of rugby union for negligence, after developing early symptoms of dementia, attributed to Chronic Traumatic Encephalopathy (CTE) caused by repetitive small knocks to the brain over time.
It will be a difficult case to prove, as there would be no 'control' case to compare with, but some American football players secured a settlement from the NFL for the same issue to the tune of around $1bn. And the FA is facing a similar bout of legal action
The repercussions for both kinds of rugby would potentially be huge.
https://www.bbc.co.uk/sport/rugby-union/55201237