In western countries, injuries remain the leading cause of death in young adults (Jennett B. Epidemiology of head injury. J Neurol Neurosurg Psychiatry 1996; 60: 362-369). Worldwide, injuries are estimated to account for 15% of the burden of death and disability, and are projected to account for 20% in 2020 (Ad Hoc Committee on Health Research Relating to Future Intervention Options. Investing in Health Research and Development (Document TDR/Gen/96.1). Geneva: World Health Organisation, 1996). In developing countries road traffic injuries in particular are increasing in incidence and injuries are projected to be the third leading cause of death and disability worldwide by 2020 (Ad Hoc Committee on Health Research Relating to Future Intervention Options. Investing in Health Research and Development (Document TDR/Gen/96.1). Geneva: World Health Organisation, 1996). Head injury accounts for up to half of all deaths from trauma (Kraus J. Epidemiology of head injury. In: Cooper PR, Ed. Head Injury, 3rd ed. Baltimore, MD: William Wilkins, 1993), and in addition to causing death often causes severe and long-lasting functional impairment in survivors.