You can read the story here. I believe
Sad, very sad but not surprising.
Between the drugs, drinking and pounding to his head he probably took part in as soon as he was of the age fighting was allowed in hockey he was bound to have brain damage.
I always liked Probert. While known mainly as a goon the guy could skate a regular shift and twice had 20+ goals in the NHL.
His season in 1987-88 might be one of the greatest single seasons by anyone who was considered a goon.
62 points and 398 PMs in the regular season and 21 points in only 16 playoff games. This showed he could actually be played in the playoffs unlike many goons who don't come out of the press box that time of year.