Exactly. What is not clear to me is whether the chronic traumatic encephalopathy (CTE) from football, boxing etc, is just from the repeated blows to the head o

Exactly. What is not clear to me is whether the chronic traumatic encephalopathy (CTE) from football, boxing etc, is just from the repeated blows to the head or if actual repeated/severe concussions are required. Is there a threshold of head trauma that will not cause CTE or is it all just a matter of degree such that we get a small amount of CTE even with minor blows to the head, and it just accumulates.