Severe head injury (SHI) and traumatic brain injury (TBI) are widespread and have a tremendous impact. “They are the leading cause of death in children and young adults (<25 years) and account for a quarter of all deaths in the five to 15 years age group”. Following initial impact, glutamate levels rise and cause excitotoxic damage in a process that has been well characterized. With its ability to reduce glutamate levels, NAAG inhibition has shown promise in preventing neurological damage associated with SHI and TBI.