Following the apparent suicide of NFL player Junior Seau last May, an initial autopsy showed no signs of head trauma. But a more in-depth analysis by the National Institutes of Health found that Seau had degenerative brain disease. The NIH study into Seau’s brain revealed he had abnormalities that were consistent with chronic traumatic encephalopathy (CTE).

The NIH revealed their findings to the Associated Press on Thursday, saying they were consistent with autopsies done on people “with exposure to repetitive head injuries.” The postmortem diagnosis seems to have provided some closure for Seau’s family, who requested the deeper analysis following the initial autopsy.

Here’s the Associated Press, quoting Seau’s son Tyler: “I was not surprised after learning a little about CTE that he had it … I don’t think any of us were aware of the side effects that could be going on with head trauma until he passed away. We didn’t know his behavior was from head trauma.”

Dozens of football have had CTE and the disease has become so synonymous with long-term health problems in NFL players that the league has given $30 million to the NIH for research. The NFL also faces lawsuits from 3,818 former players, by the AP’s count, including 26 hall-of-famers, who allege that the league withheld information on the long-term health effects of concussions.

While the cause of CTE is pretty established, its symptoms are a bit less understood.