BMX legend Dave Mirra suffered from brain disease before dying of a self inflicted gunshot wound ... according to reports.
Mirra's family donated his brain to a neuropathologist shortly after his death in February. Reports say a doctor determined Mirra's brain showed signs of CTE -- a neurodegenerative disease linked to repeated head injuries.
CTE has been linked to dementia, depression and aggression to name a few.
Scores of pro football players have suffered from CTE -- Mirra is the first extreme sports athlete to be diagnosed with the disease.
