After Cleveland Browns quarterback Colt McCoy returned to a game in December 2011 despite not being checked for a head injury following an against-the-rules hit to the helmet, the league put certified athletic trainers in booths above the field to watch for injuries and added video feeds on sidelines to make it easier to track dangerous hits immediately.
Aiello said that video was used by the Bears and 49ers to look at their quarterbacks' injuries.
The league spokesman declined to comment on Harbaugh's description of what happened with Smith: The QB threw a TD pass a half-dozen plays after he began experiencing blurred vision on a 1-yard keeper — and a dozen plays after taking a vicious hit from St. Louis linebacker Jo-Lonn Dunbar.
Smith scrambled to his left and started to slide before turning when Dunbar got him in the back of the neck with 1:10 left in the first quarter. He briefly grabbed his face mask and grimaced but stayed in the game
"He said he had the blurred vision after the quarterback sneak," Harbaugh said. "There's no telling. Did that earlier hit contribute? I don't know. I don't know Alex knows for sure, either."
Added Harbaugh: "You don't want him out there with blurred vision. ... He came up from the sneak and he had blurred vision and he felt that it would go away. He came over to the sideline and sat down and felt it would go away and it didn't."
Bears coach Lovie Smith said Cutler showed no symptoms of a concussion immediately after a helmet-to-helmet hit from Houston's Tim Dobbins in the second quarter. Cutler finished the half, then was held out after halftime. While the play with Dobbins' hit was being reviewed by the officials, Smith said: "Our trainers talked to him, evaluated him; he was fine from there. Players in the huddle didn't see anything wrong with him at the time."
Vick, meanwhile, was diagnosed with a "pretty significant" concussion, coach Andy Reid said. Reid wouldn't rule Vick out for next Sunday's game at the Washington Redskins; rookie Nick Foles would play if Vick doesn't.
"You've got to get ready for both. We're not too sure what the situation is, so we'll wait and see there," Redskins coach Mike Shanahan said. "With the concussion that he had, I don't think you're really sure."
AP Sports Writers Janie McCauley, Andrew Seligman, Joseph White, John Wawrow and Dan Gelston contributed to this report.
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