The public understanding of TBI is so poor that it is officially referred to by the US National Center for Injury Prevention and Control as "the silent epidemic." In the acute phase, the usual radiological examinations are not sensitive to TBI and diffuse axonal injury (DAI). There is a significant amount of false negatives with CT scans administered in the ER.
Concussion is the acute psychological experience of trauma through head impact, acceleration and an alteration or limited loss of consciousness (LOC)(Parker, 2012). Generally, it is without sufficient neurotrauma to be detected by neuroimaging procedures. Imaging procedures to capture perfusion and microscopic blood flow problems are not routinely done.
The problem of repeated, sub concussive hits on NFL players was recently described by researchers at Department of Veterans Affairs and Boston University who found that 96% of former NFL players tested for evidence of degenerative brain disease with 79% of all football players tested-who played at all levels-showing signs of the disease. The researchers tested the brains of 165 former football players who competed at the high school, college, semi-pro or professional level. Of those tested, 131 showed signs of chronic traumatic encephalopathy (CTE). The findings show that 40% of those who tested positive were the offensive and defensive linemen who came into contact with one another on every play of the game. This finding supports past research suggesting that it is the repeat, more minor head trauma that occurs regularly in football that may pose the greatest risk to players, as opposed to just the sometimes violent collisions that cause concussions. There is a limitation to the research in that individuals and families who agreed to the testing are more likely those who suspected they might have the disease. CTE can only be diagnosed after death.
Concussions themselves are not "one time" events. There is a first injury (blow to the head) and second injury which is the cascade of damaging neurobiological events and neurocellular post-injury. (Leiningeretal, 1990), found that even the most sensitive neuropsychological tests do not tap some subtle processing neurological deficits.
There is a common misconception that concussion is a condition that quickly resolves. The science is at variance with this impression; it is asserted that of approximately 230,000 individuals hospitalized annually with TBI, an estimated 83,000 are discharged with TBI-related deficits. There are 5.3 million Americans who are estimated to have TBI-related disability.
(Parker 2012) notes that many clinicians do not recognize potential TBI, or if in doubt, do not alert their patients that later discomforts should be further evaluated.
Chris Borland, linebacker for the San Francisco 49ers retired at 24, stating "I just honestly want to do what is best for my health; from what I remembered and what I've experienced, I don't think it's worth the risk." He began to have misgivings during training camp. He said he sustained a concussion during a play, but played through it. He states, "I just thought to myself, 'what am I doing?' Is this how I want to live my adult life, banging my head, especially with what I've learned and know about the damages?"
Chris gets it right about the long range dangers of concussions. A recent report notes a nationwide decline in football participation at high schools. The parents of players are concerned about concussions.
On a national basis, research findings and changes in participation in football point to a changing landscape in the football arena. Chris Borland spoke out against the unnecessary violence in football. Parents are speaking out. They are listening to the danger signs. But is the NFL? Only time will tell.