Pugilistic dementia. Some boxers manage to avoid it. Archie Moore was in his 80s when he passed and showed no signs of dementia outside of the slowing down that comes with aging. Jake LaMotta had dementia, but he was so old at 95, it's hard to say if his dementia came from old age or boxing.
Heartbreaking to see Tommy Hearns in this condition. The "Hit Man" along with "Smokin Joe" Frazier are my two all time favorite boxers! (I hope Tommy is as well cared for as possible for however many years he has going forward on this Earth.)