Each year about 1,5 million people are affected by traumatic brain injury (TBI) in the EU, a disorder caused by an external force to the head typically during a road traffic or sport accident or a fall. 70,000 of these patients die and 100,000 become disabled. Since these are mostly children and young adults, TBI is the most frequent cause of death and disability in this particularly vulnerable population. While many lives were saved in recent years due to improved emergency and hospital care, it has become evident that surviving patients often suffer from various chronic brain disorders such as epilepsy, depression and progressive dementia for their entire remaining life. Currently, we lack treatments that could tackle these chronic complications induced by TBI (chronic TBI). The current application aims to bring together the best and most experienced European TBI researchers and to investigate whether the brain stays inflamed long-term - possibly for years - after the initial injury and whether this long-lasting (chronic) inflammation is involved in the above mentioned chronic complications induced by TBI. The ultimate aim of the project is to determine the underlying causes of chronic TBI for developing an effective cure. In order to achieve this goal our consortium will use animal models of TBI and investigate TBI patients with innovative state-of-the-art histological and imaging technologies. We will first monitor inflammation and degeneration of the brain over months in animal models (corresponding to years in humans). In parallel, we will investigate how this chronic inflammation affects essential brain components in the human brain. Finally, we will block the chronic inflammation of the brain with small molecules and antibody-based drugs in experimental TBI models in order to develop novel treatments for chronic TBI.