A number of high-profile former players are involved.
World Cup-winner Steve Thompson is leading a group of players suing rugby authorities for negligence.
The former England hooker has been diagnosed with early onset dementia.
It also includes ex-England player Michael Lipman as well as Wales' Alix Popham.
Thompson says he can’t remember England’s games in the 2003 World Cup, and often forgets his wife’s name: