Glenn played as a backup Sunday against Carolina but had to leave at halftime because his headaches worsened.
The Packers' medical staff cleared Glenn to play last week after a CT scan (computerized tomography) showed no abnormalities and Glenn reported his headaches had diminished. But after taking a couple hits his headaches got worse and he didn't return from the locker room at halftime.
"He's not someone who's had concussion issues or a history of concussions in the past," coach Mike Sherman said. "We're going to investigate this, look real hard and see if we can come up with an answer."
Glenn has undergone repeated tests but nothing has revealed anything abnormal, so the Packers are moving to the next stage.
The Packers treated Glenn for what they thought was a mild concussion in the opener Sept. 8 against Atlanta after a hit by safety Gerald McBurrows. Subsequent tests showed Glenn isn't suffering from a concussion. There are a number of other conditions related to head trauma that Glenn could be suffering from, including post-traumatic syndrome.
"It is a gray area and you're dealing with one of the most important parts of the body," Sherman said. "I have no input in regard to what the doctors say. I'm very conservative in regard to head injuries and we have been with Terry.
"Terry wanted to play in the ball game, wanted to give it a shot, to see if he could get through the game and deal with it. It seemed to digress at the end of the first half. It's an area you're very concerned about. I would never put a player at risk if I thought there was a risk involved."
Packers WR Glenn to see head trauma specialist
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