With today's disclosure that former NFL star linebacker Junior Seau had a degenerative brain disease known as CTE when he committed suicide last year, here's a rundown on the condition and Philadelphia players known to have suffered from it.
What does CTE stand for?
CTE stands for chronic traumatic encephalopathy.
What is it?
CTE is a degenerative brain disease caused by repetitive head trauma. The trauma triggers progressive brain-tissue degeneration, including build-up of a protein called tau, according to Boston University's Center for the Study of Traumatic Encephalopathy.
What are some effects of the disease?
BU experts say CTE is associated with memory loss, confusion, impaired judgment, impulse-control problems, aggression, depression and dementia. These symptoms can appear months or years after the trauma.
Who suffers from CTE?
It is most frequently diagnosed in athletes who have experienced repeated head trauma, such as football and hockey players. A 2012 study found the disease in donated brains of 34 professional football players, nine men who played college football and six who played the game in high school. It has also been diagnosed in soldiers.
Why has CTE been in the news in recent years?
The families of former football players who have died -- often after showing signs of the disease -- have allowed researchers to study the players' brains. Those examinations have revealed the extent of the condition. In addition, thousands of former players have sued the NFL, alleging that the league withheld information about brain trauma and didn't do enough to prevent or treat concussions.
How has the disease affected Philadelphia-area football players?
In 2006, former Philadelphia Eagles player Andre Waters committed suicide by shooting himself in Tampa. The 44-year-old ex-defensive back's brain was examined by experts, who determined that he had suffered brain damage from numerous concussions sustained over his football career. That trauma led to his depression and ultimate death, doctors who studied his brain say. Waters played for the Eagles from 1984 to 1993; he then played for the Arizona Cardinals.
Former Eagles lineman Tom McHale died from an accidental drug overdose in May 2008, at age 45. He was diagnosed post-mortem with CTE. McHale played for the Eagles in 1993 and 1994; he also played for the Tampa Bay Buccaneers and Miami Dolphins.
In April 2010, University of Pennsylvania lineman Owen Thomas hanged himself. Boston University researchers examined his brain after his death and an autopsy revealed early stages of CTE. It was the first time the disease had been discovered in a college player.
Ollie Matson, who played for the Eagles from 1964 to 1966, died in February 2011 with dementia and stage 4 CTE, according to the New York Times. He spent a total of 14 seasons in NFL, playing in Chicago, Los Angeles and Detroit before joining the Eagles.