Considering the potential cumulative effects of repetitive head impact exposure, we need sensitive biomarkers to track short- and long-term neurological consequences in athletes that are at increased risk of developing brain health issues. Circulating small extracellular vesicles, less than ~200 nanometers in size, traffic biological molecules throughout the body and may have diagnostic value as biomarkers for disease. Extracellular vesicles, released by cells during normal and pathological conditions, contain a variety of molecular cargo including protein, DNA, and RNA from their cell of origin. Extracellular vesicles and their cargo can be isolated from biofluid and serve as excellent liquid biopsies of numerous disease states, such as Alzheimer’s disease and Parkinson's disease. My dissertation topic explores the effects of repetitive subconcussive head impacts on circulating extracellular vesicles in college-aged athletes. Many athletes experience a high incidence of subconcussive head impacts over the course of their lives. These impacts have been shown to cause significant detrimental neurological effects if experienced repeatedly, including cognitive impairment and mood dysfunction. In our most recent work, we identified a microRNA panel associated with repetitive head impact, while identifying messenger RNA targets of previously unknown miR-7844-5p. We are now assessing the effects of head impact changes over short and long periods of time in soccer athletes. My current research aims include focusing specifically on brain-derived subpopulations of extracellular vesicles using a bead-based immunocapture method. We are also exploring extracellular vesicle microRNA cargo packaging as a biomarker of neuroinflammation and/or damage to the blood-brain barrier in athletes. The long term goal of my dissertation topic is identifying biomarkers of specific neurological damage to assist athletes in returning to play.