NEW YORK -- Rangers enforcer Derek Boogaard suffered from chronic traumatic encephalopathy, a degenerative brain ailment related to Alzheimer's disease that is caused by repeated blows to the head, the New York Times reported.
The 28-year-old Boogaard, who died in May of an accidental overdose of alcohol and oxycodone, was found to have had CTE -- which can be diagnosed only after the death of the patient, according to the third story of an extensive three-part series on Boogaard posted on the newspaper's website Monday night.
Dr. Ann McKee, one of four co-directors of Boston University's Center for the Study of Traumatic Encephalopathy and the director of the center's brain bank, saw signature brown spots near the outer surface of Boogaard's brain, which are revealing signs of CTE.
Such damage in someone as young as Boogaard was surprising. Symptoms of the condition include memory loss, impulsiveness, mood swings, and addiction.
"To see this amount? That's a 'wow' moment," McKee said of the damage to Boogaard's brain tissue. "This is all going bad."
The disease was more advanced in Boogaard than it was in famed enforcer Bob Probert, who died of heart failure in 2010 at 45. He played 16 seasons in the NHL and often struggled with alcohol and drug addiction.
Reggie Fleming, who was 73, and 59-year-old Rick Martin, were other hockey players who were found to have CTE.
CTE has also been found by researchers in the brains of numerous deceased former NFL players, including Dave Duerson, Chris Henry, Mike Webster, Cookie Gilchrist and Andre Waters.
Information from The Associated Press was used in this report.