Published data suggest that white matter damage following TBI may play a critical role in the chronic progression of neuronal degeneration resulting in regional brain atrophy in distal areas that are not directly affected by primary injury [19], an observation consistent with our previous reports demonstrating chronic white matter degradation following focal cortical injury [38] and suggesting involvement of caspase-3-mediated apoptosis as a possible mechanism involved in this process [39]. This evidence concerns the gene CASP3 and Atrophy.