Adult patients, age ≥ 18 years, with clinically diagnosed mild, moderate or severe brain trauma will be asked to participate in the study. If such possible subjects are either unconscious, sedated or confused to the extent, that no personal decisions can be drawn, her next of kin will be asked for the permission to include the subject in question to the study. Control group subjects will be patients with acute orthopaedic injuries without any signs of eventual concomitant brain trauma of any degree. The source populations will consist of citizens from the local catchment areas of the participating centres.