Changes in Brain White Matter After Multiple Sub-Concussive Head Blows Principal Investigators Dr. Jeffrey J. Bazarian Introduction Head blows that do not result in a concussion are a common occurrence in contact sports and are generally thought to be harmless to the athlete. However, a recent study performed by the Bazarian and Blyth Lab identified significant brain white matter changes on diffusion tensor imaging (DTI) after multiple sub-concussive head blows among a group of high school football and hockey players. This study seeks to confirm these findings in a group of college football players and to increase the understanding of the nature of this type of brain injury so that it can be prevented. While the neurologic risks of concussion are just beginning to be appreciated, the risks posed by cumulative sub-concussive head blows are potentially much larger, as they affect virtually every athlete involved in contact sports on an almost daily basis. Purpose In order to prevent sub-concussive head blows from causing neurologic harm to contact sport athletes in the future, this study proposes to examine the impact forces associated with brain injury, the individual-level determinants of recovery from brain injury, and the effect of rest on recovery from brain injury. Design Methods We propose a prospective study of 10 college football players and 5 non-athlete controls. Each subject will undergo DTI scanning, cognitive testing with ImPACT, serum collection for ApoA1 analysis, and balance testing at the beginning of the football season, at the end of the football season, and after 6 months of rest from contact sports. Force data will be collected on football players equipped with Riddell Revolution® IQ™ helmets connected to the Head Impact Telemetry System (HITS). Apoε genotyping will occur at the beginning of the season. Significance of the Study A thorough understanding of these factors is a necessary prerequisite to the development of effective prevention and treatment startegies.