NORWOOD (CBS) – The parents of a Wrentham teenager say his frightening disappearance this week may have been linked to the lingering effects of a concussion.

17-year-old Matthew Glass, a senior at King Philip Regional High School, turned up at a house in Dedham Thursday night.

WBZ NewsRadio 1030′s Karen Twomey reports

He had been missing for two days.

WBZ-TV’s Christina Hager reports

It’s not known how he ended up at a stranger’s home in Dedham, but he was said to be disoriented and dehydrated.

He was taken to Norwood Hospital, where he was reunited with his parents.

Michael and Diane Glass told reporters Friday their son is no longer disoriented, but he still does not remember where he has been this week.

“This is a really positive outcome because we really did fear the worst given that he had cut off all contact and the fact that he’s so confused and doesn’t really know what happened the last two days. We know we’re lucky to have him and to have found him. We’re just so relieved,” Diane said.

“As you can imagine we haven’t slept in two days and it was just such a relief to see him. We weren’t sure until we got to the hospital what he was going to look like.”

His parents say they’re relieved he’s safe, but it’s believed he’s still feeling the effects of a concussion he suffered last fall.

WBZ-TV’s Sera Congi reports

“He’s still in the hospital, he’s still seeing specialists. He’s is confused and we’re going to get him the help that he needs to get back on track. We do think this is the lingering effects of a very bad concussion,” Diane said.

“People think ‘Oh, you have a concussion, 2, 3 weeks, a month later you’re fine. But all the documentation is showing that that’s just not true,” his father Michael said.

“He has lost consciousness twice, where he was found face down on the floor.”

The injury was severe enough to keep him out of football this season.

Police say there was no criminal activity, Glass was not abducted and there were no drugs in his system.