To be clear, a concussion can occur after many blows to the head and not just one particular hit. Chronic traumatic encephalopathy (CTE), which has been the big topic among the NFL players, is caused by repeated damage to the brain by continuous blows to the head. CTE occurs over time and for the most part we have seen it predominantly in deceased NFL players. But college football player at Iowa was diagnosed with CTE after his unexpected suicide, and a high school player whose life was cut short also was diagnosed with early signs of CTE.
So what does this data mean?