Cantu said he had seen comments in the New York Times on Monday by Dr. Daniel Perl, a professor of pathology at the Uniformed Services of the University of Health Sciences. Called upon to offer an independent opinion, Perl told the paper in speaking of Thomas that it is "not unreasonable that aspects of his behavior were related to the underlying brain disease that was detected." While Cantu conceded that Perl could be correct, it has been his experience that CTE does not become symptomatic until well along in life.
"There is no question that [Thomas] had two or more areas of his brain that showed abnormal tau protein depositions," said Cantu. "No one at age 21 should have any tau. Zip. Zero. None . . . But in comparison to some of the pro football players and some of the boxers we have studied, there was way less of it."
Thomas is the youngest former college athlete to have been found with CTE. But Cantu said that an autopsy performed on an 18-year-old football and rugby player also showed traces of it - "if [Thomas] was 1.5, the 18-year-old would have been a .5." Cantu added that the 18-year-old, who died of a head injury during a rugby game, was "asymptomatic," which is to say he had yet to experience some of the disorders that can afflict older former players. Insofar as Thomas is concerned, Cantu said that no one can say with certainty how the relatively small presence of CTE could have weighed in his outcome.
"Could he have had an inherited tendency toward depression or could he have had some setback?" said Cantu. "Or did he do it because of CTE? If you were to ask me, I would say more likely than not the answer is no."
Cantu pointed to the case of Chris Henry, the former Cincinnati Bengals player who died at age 26 when he jumped off the rear of a truck. An autopsy revealed the presence of CTE in Henry.
"Do I think Henry jumped off the back of that truck because of CTE?" said Cantu. "He had been known for aggressive behavior and the inability to control his temper his whole life. So the answer is no."
But Cantu does see a linkage between CTE and erratic behavior later in life. The evidence can be seen under the microscope in the appearance of tau protein depositions. The CTE reveals itself in brown spotting.
"In the older players we have looked at, there is extensive destruction along the medial temporal lobe," said Cantu. "This is the area that controls emotion, memory, addiction and so on."
But Cantu stressed how vital it is to pay attention to the fact that Thomas even had CTE at such a young age. He compared it to seeing someone with the presence of arterial-sclerotic damage as an 18-year-old. While he or she may not be experiencing symptoms of heart disease at that age, Cantu said it could well be a predictor of more severe problems to come unless there are changes in diet and such. In that CTE is irreversible, Cantu said that players are prone to accumulated damage beginning at an early age.
CSTE co-director Chris Nowinski echoed that.
"This is the evidence we need to show that this disease can start very young," said Nowinski, the Harvard-educated former pro wrestler who founded the Sports Legacy Institute in an effort to catalog cases of brain trauma. He agreed that in the case of Thomas, "you can never connect pathology to a single decision in one person. That is not the focus of these findings."
Nowinski said "the most significant takeaway" is that someone who plays football from age 9 to 21 can develop CTE. "You do not have to be an NFL star . . . If Owen had lived, the disease could have seriously impaired his quality of life."
Nowinski added that "developing brains are most sensitive to brain trauma" and called upon youth football leagues to offer players even greater protections.
"We have to take responsibility for creating a game in which children get hit in the head 1,000 times a year," said Nowinski, whose organization has issued safety guidelines that include mandatory education for coaches, parents and players to help them identify concussions. He added that it is crucial that there be a "total reduction of brain trauma," which can be achieved by rethinking the belief that "the only way you can become a good football player is by butting heads 50 times a day in practice."
"We could actually reinvent football practice to include virtually no brain trauma, and still have contact on the weekend," said Nowinski. "That would reduce brain trauma by 75 percent."
Nowinski paused and added, "We have to start using our brains."