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Sub-Concussive Brain Trauma Causes Auto-Immune Brain Response

Until now it was thought the brain could only be damaged by trauma sufficient to cause a concussion – an event marked by loss of consciousness or by detectable alteration of consciousness (such as dazing, confusion or memory loss). A new study of 67 college football players shows that sub-concussive trauma (trauma below the level required to cause a concussion) can damage the brain by leaking a protein called S100B into the bloodsteam that causes antibodies to form.These antibodies attack the protein and set off an auto-immune response in the brain of the same type that researchers have seen cause dementia. Prior to this study S100B had only been seen in head-injured athletes who had sustained concussions.

The study concluded that the more sub-concussive head trauma an athelete endures the greater the amount of protein S100B circulating in the brain’s bloodstream, and the greater the auto-immune response. The study was conducted by Damir Janigro, Ph.D., the director of cerebrovascular research in Cleveland Clinic’s Lerner Research Institute, and his collaborators Nicola Marchi, Ph.D., of Cleveland Clinic and Jeffrey Bazarian, M.D., M.P.H., of the Clinical and Translational Science Institute at the University of Rochester Medical Center. A sideline bloodtest costing $40 can be done to detect S100B after a football player suffers a hard hit even if he isn’t knocked out or put into an obviously confused state. Any player with elevated S100B should be evaluated by a neurologist and kept from play as the doctor directs. The study can be found at in the March 6, 2013 online issue of PloS One.