Officials said the disease had advanced to a stage rarely seen in someone Tyler Sash's age, 27
Credit: AP

Former New York Giants safety Tyler Sash has been diagnosed with chronic traumatic encephalopathy (CTE) nearly five months after his death.

Officials with Boston University and the Concussion Legacy Foundation notified the Sash family of the diagnosis, and said the disease (diagnosed posthumously) had advanced to a stage rarely seen in someone Sash’s age, 27, The New York Times reports.

“My son knew something was wrong, but he couldn’t express it,” Barnetta Sash told the Times” of her son’s disease. “He was such a good person, and it’s sad that he struggled with this – not knowing where to go with it.”

She said the diagnosis brought clarity to Sash’s death.

“Now it makes sense,” she told the Times. “The part of the brain that controls impulses, decision-making and reasoning was damaged badly.”

Sash was found dead at his Oskaloosa, Iowa, home on Sept. 8. The Iowa State Medical Examiner’s office later said in a statement that the man died of an accidental overdose from mixing two pain medications, hydrocodone and methadone.

Sash is one of many former football players diagnosed with the degenerative disease.

In November, Frank Gifford‘s family revealed that the late NFL broadcaster, and former New York Giants star, suffered from CTE.

Recently, Dr. Bennet Omalu – who inspired the movie Concussion starring Will Smith – told PEOPLE that Hall of Famer O.J. Simpson said he is sure the star has the disease – “I would bet my medical license that he has CTE,” he said.

Tonissa Murdock, the sister of former NFL running back Lawrence Phillips, who died earlier this month, told PEOPLE that the family donated the man’s brain to researchers studying CTE.

Sash played football at the University of Iowa from 2008-2010, entering the draft after his junior season in college.

He was drafted by the Giants in the sixth round and won the 2012 Super Bowl with the team. He was cut by the Giants before the 2013 season.