Greg Johnson, a former NHL player, has been posthumously diagnosed with chronic traumatic encephalopathy (CTE), a degenerative brain disease linked to repeated head trauma. Johnson, who died by suicide in 2019 at age 48, was diagnosed by Dr. Ann McKee of the Boston University CTE Center. His family and the Concussion Legacy Foundation are urging the NHL to acknowledge the link between repetitive head impacts and CTE and to take action to protect players. Despite this, NHL commissioner Gary Bettman has denied a definitive connection between head trauma and CTE. Johnson's case is part of a broader pattern, with 17 out of 18 NHL players studied being diagnosed with CTE. The diagnosis has sparked renewed calls for the NHL to address the long-term risks of concussions and other head injuries in hockey.