He said he has also spoken to rugby union and league players associations about it. “They re all aware of the fact that the incontrovertible truth is collision-based sports create long-term neurological damage. “What we are seeing is the classic tobacco play where the authorities cobble together a cabal of scientists to deny, deny, deny. “So I think we re up against it, it ll be a long fight.” Chronic traumatic encephalopathy (CTE) is the brain disease affecting retired players, and it starts off as chronic neuropathic logical impairment (CNI), Jess said. “We tracked it over five-year period … the measurable changes to the structure of the brain, where the player was engaged in repetitive collisions.