The presence in the brain of a particular protein shortly after concussion predicts the severity of symptoms.

In Brain Science, Concussion by Brainy Days Ahead

SNTF is a protein that is not detectable in healthy human brains, but is produced in the brain under conditions where nerve cells are traumatized and begin to die. Researchers have found that elevated levels of SNTF in the brain found shortly after sports-related concussion can predict the severity of post-concussion symptoms in professional athletes.