Still, when he began having trouble late in his life finding the right word, keeping things organized, remembering why he was going to the doctor or controlling his temper, relatives grew concerned.
After he died last year at the age of 78, they agreed to donate his brain to researchers studying a degenerative disease increasingly found in football players and other athletes who have absorbed repeated blows to the head. This week the results came in: Carpenter had an advanced form of Chronic Traumatic Encephelopathy.
"Concussions aren't necessary for CTE to exist," said Dr. Robert Cantu, a Boston University researcher working on the project in conjunction with the Veterans Administration Center for the Study of Traumatic Encephalopathy. "Even if he didn't have any concussions, the amount of subconcussive trauma that he had -- he probably had between 1,000 and 1,500 subconcussive blows a year, just from practice and play in games."
Concussions are a growing concern among sports leagues, especially since the suicide of NFL defensive back Dave Duerson and the death of NHL enforcer Derek Boogaard; both were found to suffer from CTE, which can cause memory loss, disorientation, poor decision-making, and depression that can lead to drug use and even suicide.
The NFL and NHL have taken steps to crack down on the more violent head hits, and the pro football league has also cut back on full-contact practices that contribute to the wear and tear on all parts of the players' bodies.
For now, CTE can only be diagnosed by a posthumous brain exam.
Copyright 2011 by The Associated Press