Hits to the head that can cause concussions were the main topic as NHL GM's began their annual meetings Monday, according to an Associated Press report. A discussion of a two-year independent medical study undertaken by the league included a video presentation showing footage of a number of well-known hits to the head during games. The league estimates there are 60,000 to 70,000 body hits during a season, and during the past 2 1/2 years there have been 200 concussions reported among players.