GRC: BMX star, ex-Subaru driver Mirra had CTE

BMX star and former Subaru factory GRC driver Dave Mirra, who died from a self-inflicted gunshot wound in February, was found to have chronic traumatic encephalopathy (CTE), a progressive degenerative disease of the brain, ESPN The Magazine reports. Mirra is believed to be the first action sports athlete to be diagnosed with CTE.

University of Toronto neuropathologist Dr. Lili-Naz Hazrati was granted access to Mirra's brain by his family after his death and concluded that the tau protein deposits found were "indistinguishable from the kind that have been found in the brains of former football and hockey players with CTE," she told ESPN. At the family's request, Hazrati sent images of prepared slides – without any background information or Mirra's identity – to additional U.S. and Canadian neuropathologists for their opinions. Each confirmed the diagnosis of CTE, which currently can only be determined after death by analyzing brain tissue.

CTE is increasingly being diagnosed in former athletes, as well as military veterans and others with a history of repetitive brain trauma. 

Mirra, 41, was part of Subaru's GRC line-up from 2011 until 2013, earning a best result of fourth in Atlanta in 2014, although he was better known for his exploits on two wheels: he was an icon in the BMX and extreme sports world, and until 2013 his haul of 24 X Games medals – 14 of which were gold – was a series record.

But he was believed to have suffered numerous concussions. The tau protein deposits were found in Mirra's frontal and temporal lobes and Hazrati said "it's assumed it is related to multiple concussions that happened years before."

"It validates what we have been thinking about brain injuries in boxers and football players," Hazrati told ESPN. "The key is brain injury. Regardless of how you get it, through BMX or hockey, you are at risk for this."

Mirra appeared in several video games and also hosted the MTV show "Real World/Real Rules Challenge," and had become a focal point for the thriving BMX community in the town of Greenville, North Carolina, where he lived.