Type of Brain Damage, Like Multiple Sclerosis, May Be Caused by Autoimmune Disorder
Repeat injuries to the head are widely considered to be dangerous and to cause neurological problems later in life. The NFL has brought a lot of attention to this problem, particularly in the cases of the much-publicized chronic traumatic encephalopathy. New research indicates that hits to the head may cause an autoimmune problem, like multiple sclerosis, to lead to brain damage. The findings may lead to better treatment to prevent problems in NFL players and college football players as well.
Researchers examined a protein biomarker called S100B, which is an indicator of brain injury. It was present to varying degrees in 67 football players after a game, even though none of them had symptoms of concussion. As could be expected, tests revealed that levels of S100B were higher in players who had sustained repeated hits to the head, while players who were sidelined had lower amounts of the biomarker.
The brain is the only organ with a unique barrier, appropriately named the blood-brain barrier. When it works properly, it allows the brain to be bathed in proteins and molecules that help nourish it and to protect it from foreign invaders. However, with hits to the head, the blood-brain barrier can create tiny holes that can allow room for invaders to enter and nourishment to leave.
The body recognizes this problem and attacks S100B in the bloodstream. However, antibodies become too vigorous and sneak through the new holes in the blood-brain barrier to attack the brain cells that produced the biomarker in the first place. What's worse is that S100B accumulates in the dendric cells, which regulate the body's autoimmune responses. That means that, as players sustain repeated hits to the head during football season, the biomarker paves the way for more of these attacks.
"Our theory is plausible as an explanation for how routine head hits that come with playing football can lead to severe neuro-degeneration later in life," Dr. Jeffrey J. Bazarian, an associate professor at the University of Rochester Medical Center, said in a statement. "If others confirm this, it could present options with drugs that influence the immune response."
The study was published in the journal PLoS One.