"When Sidney Crosby suffers concussion symptoms, the entire National Hockey League gets a headache.

It would be bad enough if Crosby was the only elite player currently sidelined with a concussion, or "concussion-like symptoms" as teams sometimes like to frame these injuries — semantics that don't really soften the blow to the player, his team or the league.

Sadly, Crosby has plenty of company in the proverbial NHL Quiet Room.

So much for the optimistic NHL report in mid-November that concussions were down by half compared to a year ago, while players presumably adjusted to the league's tougher stance on enforcement and suspensions where head hits were concerned."