MND is becoming as associated with rugby as Alzheimers is to former soccer players who spent years heading a ball.
Not sure if it's the sport itself or whether the players concerned were more susceptible to those specific problems.
One of those things that requires a lot more research and confirmation i think.
Although, watching a round up of the football last night , several players were sent off for some extremely dangerous challenges that might cause life changing conditions for the players they 'assaulted'.