Junior Seau, the former San Diego Charger and USC great who committed suicide last May, was suffering from Chronic Traumatic Encephalopathy (CTE).
Seau's ex-wife, Gina, and his oldest son Tyler, 23, told ABC News and ESPN that the National Institutes of Health had concluded its test of Seau's brain and discovered the chronic brain damage condition "that also has been found in dozens of deceased former players."
According to ESPN, "CTE is a progressive disease associated with repeated head trauma. Although long known to occur in boxers, it was not discovered in football players until 2005," and "researchers at Boston University recently confirmed 50 cases of CTE in former football players, including 33 who played in the NFL."
The neurodegenerative disease can "lead to dementia, memory loss and depression."
"I think it's important for everyone to know that Junior did indeed suffer from CTE," Gina Seau said. "It's important that we take steps to help these players. We certainly don't want to see anything like this happen again to any of our athletes."
According to Gina, the family was told Seau's brain injury resulted from "a lot of head-to-head collisions over the course of 20 years of playing in the NFL. And that it gradually, you know, developed the deterioration of his brain and his ability to think logically."
Dr. Russell Lonser, the former chief of surgical neurology at the NIH, who helped coordinate the study said "three independent neuropathologists from outside the NIH were given unidentified tissue from three different brains; one belonged to Seau, another to a person who had suffered from Alzheimer's Disease, and a third from a person with no history of traumatic brain injury or neurodegenerative disease."
He said those three "experts independently arrived at the same conclusion as two other government researchers: that Seau's brain showed definitive signs of CTE."
During the last years of his life, Seau's mood would change dramatically:
Tyler, whose mother was Junior Seau's high school sweetheart, and Gina both described dramatic changes they noticed in Seau during the final years of his life, including mood swings, depression, forgetfulness, insomnia and detachment.
"He would sometimes lose his temper," Tyler said. "He would get irritable over very small things. And he would take it out on not just myself but also other people that he was close to. And I didn't understand why."
Seau's mother thinks the NFL was too slow to look into concussions. Her son was never listed by any of his teams as ever having a concussion.
Moments before he took his life, Seau sent a group text to his ex-wife Gina and his four children that simply said, "I love you."
"The difference with Junior ... from an emotional standpoint (was) how detached he became emotionally," Gina said. "It was so obvious to me because early, many, many years ago, he used to be such a phenomenal communicator. If there was a problem in any relationship, whether it was between us or a relationship with one of his coaches or teammates or somewhere in the business world, he would sit down and talk about it."
Gina said Seau would never run from conflict and would always say, "let's sit down and break bread and figure this out."
Seau's family has found a bit of solace knowing his brain showed unmistakable signs of CTE. Seau was a charismatic figure beloved in the San Diego community.