TORONTO -- Testing on the brains of four deceased CFL players shows two of them suffered from a neurological disease.
Former Toronto Argonaut and Hamilton Tiger-Cat Bobby Kuntz, and Jay Roberts, an Ottawa Rough Rider, had repeated concussions during their careers, and their brains showed signs of chronic traumatic encephalopathy, or CTE.
CTE can cause memory impairment, emotional instability, erratic behavior, depression and poor impulse control, and may eventually lead to dementia.
Former Winnipeg Blue Bomber Peter Ribbins, who died in December of Parkinson's disease, and former Montreal Alouette Tony Proudfoot, who died this year of Lou Gehrig's disease, did not show signs of CTE.
Doctors say the relationship between concussions and CTE is not yet known.
Kuntz died in February after a long battle with Parkinson's disease, while Roberts died last October after suffering from dementia and lung cancer.
"While both of these men appeared to have pathological signs of CTE, they also suffered from other serious neurological and vascular related diseases," neuropathologist Dr. Lili-Naz Hazrati said. "Right now we have more questions than answers about the relationship between repeated concussions and late brain degeneration. For example, we are still trying to understand why these two players acquired CTE and the other two did not."
The brains were donated to the Canadian Sports Concussion Project at the Krembil Neuroscience Centre in Toronto.