[Epidemiology of severe cranial injuries]

Head injuries (HI) are one of the most common causes of death, morbidity and disabilities in young adults. Epidemiological studies allow a quantitative estimation in terms of incidence and a qualitative estimate for the identification of risk factors in specific populations. These estimates may enable appropriate prevention programs. Estimates of annual incidence rates depend on territories, periods and methodological tools. Annual rates for hospitalized patients are found between 150 and 300/100,000 inhabitants. Severity of HI can be assessed by the Glasgow Coma Scale (GCS), the Abbreviated Injury Scale (AIS) or the Post-Traumatic Amnesia duration. Annual incidences of severe HI will depend on the selected score: around 25/100,000 inhabitants for cerebral trauma with intracranial injuries, around 9/100,000 for the most severe HI, with an AIS maximum of 5 with coma. The male:female ratio increases with degree of severity. Traffic accidents were the most frequent cause of HI. Many patients have associated injuries, worsening the outcome. Some risk factors are considered. Preventive measures are mainly conducted for traffic accidents, and include speed limit and regulations on helmet or seat belt use. Results of these measures are analysed.