Axonal Injury Principal Investigators Dr. Jeffrey J. Bazarian Dr. Brian Blyth Introduction Mild Traumatic Brain Injury (mTBI) or concussion affects over one million patients each year in the United States. Concussion results in microscopic structural brain injury to the long processes of neurons called axons. This injury has been detectable only during post-mortem analyses. Recent advances in imaging technology have resulted in an MRI technique called diffusion tensor imaging (DTI) which now allows in vivo detection of abnormalities associated with axonal injury. Organ specific injuries, such as TBI, may also be associated with the presence of unique protein biomarkers in biological fluids. The term proteome refers to the summation of all proteins in a biological sample. Our laboratory is interested in understanding the imaging changes associated with mTBI as well as associated changes in the serum proteome. Purpose To identify and validate objective aids for the accurate diagnosis of mTBI. Design Methods Prospective cohort study, diffusion tensor imaging, proteomic analysis with both 2D gel electrophoresis and SELDI-MS, western blotting, ELISA. Significance of the study: Objective, reliable, and practical means for the diagnosis of mTBI are urgently needed. The currently used clinical criteria for the diagnosis of mTBI allow for substantial over and under diagnosis of the disease. This is especially problematic in military populations. TBI, particularly mTBI, has been called the signature injury of the Iraqi/Afghan wars. Warfighters suffering from mTBI often have subtle cognitive deficits such as impaired memory, executive function, and reaction time that may impair their abilities to protect themselves and the troops they lead. Military personnel often minimize their symptoms to avoid separation from their unit due to the diagnosis of mTBI. Conversely, there is substantial potential for others to exaggerate or even fabricate symptoms to avoid combat. Finally, there is significant overlap between the sub-acute symptoms mTBI and those of post traumatic stress disorder (PTSD).