Teen died from subdural hematoma

A Kansas coroner confirmed Thursday that the brain injury that killed Spring Hill High School football player Nathan Stiles on Oct. 29 came from a part of the 17-year-old's brain that had bled earlier this year.

Michael Handler, the Johnson County corner and a neuropathologist, informed the Stiles family Thursday that the exact cause of death was a subdural hematoma, which Nathan Stiles likely suffered Oct. 1 during Spring Hill's game against Ottawa.

"[Handler] said it was a perfect example of a subdural hematoma," Connie Stiles said. "You could see where his brain had been healing. You could see where it was starting to get better. It seems like everything can be traced back to that first hit. That's what he thinks."

The morning after the Ottawa game is when Stiles, Spring Hill's homecoming king and team captain, first began complaining of headaches. Five days later Connie Stiles took her son to Olathe Medical Center, where he underwent a CT scan and was diagnosed with a concussion.

Two weeks after that, the Stiles' family physician cleared the 17-year-old to return to the field. But just before halftime of Spring Hill's Oct. 28 game against Osawatamie, Stiles collapsed on the sideline after screaming to coaches and teammates that his head hurt. He was airlifted from the field to KU Medical Center, where he died early the following morning following heart and lung failure. Doctors told Connie Stiles that night they thought her son's brain had suffered from an "old bleed."

The Stiles family has insisted that their son's death was an accident and no one was to blame. But the coroner's report couldn't help Connie Stiles from wondering Thursday why the original brain bleed wasn't detected by the CT scan her son had been given at Olathe Medical Center.

"You just want to know," she said. "You just want an answer."

Handler said Thursday that subdural hematomas "can be tricky and they can be hard to identify." Nathan Stiles' toxicology report came back negative.

Stiles' case is also being reviewed by sports concussion expert Dr. Robert Cantu and his staff of researchers from Boston University and The Sports Legacy Institute. Cantu has yet to inform the Stiles family of his findings.

"It's not going to matter for Nathan, but it might for someone else," his mother said. "If anything went wrong here, we need to make sure it never happens to any other family again."

Wayne Drehs is a senior writer for ESPN.com.