TORONTO – Researchers at Boston University say it’s important not to over-interpret results from a study of former NHL enforcer Derek Boogaard’s brain that show early signs of a neurodegenerative disease linked to repeated brain trauma.
“However, based on the small sample of enforcers we have studied, it is possible that frequently engaging in fist fights as a hockey player may put one at increased risk for this degenerative brain disease,” said Dr. Robert Cantu, co-director of the Boston University Center for the Study of Traumatic Encephalopathy (CSTE).
Boogaard’s brain showed evidence of early stages of Chronic Traumatic Encephalopathy (CTE).
The 28-year-old Boogaard died in May of an accidental overdose of alcohol and the painkiller oxycodone. His family donated his brain to the Boston University facility for study.
CTE can only be diagnosed by examining brain tissue post-mortem.
In 277 NHL games, Boogaard scored three goals, had 589 penalty minutes and reportedly participated in 61 regular season fights, according to the Boston University report.
He reportedly fought 174 times in pro hockey.
Boogaard had not played since Dec. 9, 2010, due to fight-related injuries, including a reported concussion.
According to the Boston University report, his family reported he had “seen stars” in a game two weeks prior to his final game. Boogaard, who had been diagnosed with post-concussion syndrome twice, also spoke of having his “bell rung” at least 20 times, according to his family.
For two years prior to his death, Boogaard had other problems, the report said – drug addiction, emotional instability and problems with impulse control, along with short-term memory problems and disorientation.
That background clouds his case.
“Boogaard’s clinical history was complex, so it is unclear as to if or how much CTE contributed to his behaviour, addiction or death,” said Dr. Robert Stern, CSTE co-director and professor of neurology and neurosurgery at BU.
“However, CTE appears to be a progressive disease in some individuals, so even if it was not directly affecting Boogaard’s quality of life and overall functioning before he died, it is possible it could have in the future.”
Boogaard was diagnosed with mild CTE by neuropathologist and CSTE co-director Dr. Ann McKee, a professor of neurology and director of the CTE brain bank located at the Bedford VA Medical Center.
The Saskatchewan-raised enforcer had evidence of early CTE in his cerebral cortex, although the severity of his brain changes was more advanced than most other athletes of similar age with CTE examined by McKee.
“Unfortunately this finding does not contribute to our knowledge of the risks of normal hockey play for most participants, as very few hockey players engage in as many fights as Boogaard,” said CSTE co-director Chris Nowinski.
“Athletes and parents should know that anyone who experiences repetitive brain trauma may be at risk to develop CTE, but we are hopeful that risk is small in hockey.”
Nowinski says two other young non-NHL professional hockey players studied did not show signs of CTE at post-mortem examination.
McKee has completed the analysis of the brains of more than 70 former athletes – more than 50 have shown evidence of CTE, including 14 of 15 former NFL players, as well as college and high school football players, other hockey players, pro wrestlers and boxers.
Early evidence of CTE has been found in individuals as young as 17.
The Boogaard family requested that the diagnosis be made public. A full report of Boogaard’s brain tissue analysis is embargoed pending publication of the study in an academic medical journal.
