Trauma brain injury following a road traffic accident: Data from the Rhône Register, France

Introduction Road accidents cause serious cranial lesions and affect a young population. They constitute a major public health problem in terms of mortality and morbidity. The objective is to describe the cranial trauma resulting from a road accident according to the accidental and individual characteristics of the casualties, the severity of injuries and evolution in time. Methods The data come from the Rhone Register of victims from road traffic accidents. It is a permanent and exhaustive collection of any person killed or injured as a result of an accident occurring in the Rhone area. It has its source in the health environment. The information collected concerns the victim, his accident, his injuries and outcome. The lesions are coded according to the Abbreviated Injury Scale (AIS), which has six levels of severity ranging from 1 (minor) to 6 (fatal). The selected victims are those with cranio-encephalic lesions, injured during the period 2005–2014. Results Over the 2005–2014 period, the Registry counted 4913 victims with traumatic brain injuries. The average annual incidence is 28.5 traumatic brain injuries per 100,000 population. The sex ratio is 2.6. There is a shift in the peak of incidence between men and women, earlier and more marked in men (15–19 years) than women (20–24 years). Victims with traumatic brain injuries are mainly motorists (36%), followed by motorized two-wheelers (24%), pedestrians and cyclists (17% each). The lethality is 7.7%. Severe head injuries (AIS ≥ 3) were less observed in two-wheeled motorized helmet users: 26% versus 37% for those who did not wear a helmet. The base of the skull is more often injured than the vault. The most frequent intra-cranial lesions are, in order of frequency, subarachnoid hemorrhages (15%), brain contusions (8%), subdural haematomas (7%), cerebral edemas (6%), intracerebral haematomas (3%), and finally the extra-durals (3%). The injuries of cerebellum (2%) of brainstem (1%) and vascular nervous system (1%) are less frequent. The type of lesion varies according to the types of users: subdural haematomas are frequent in pedestrians; extra-dural haematomas are more common in motorized and non-motorized two-wheelers users; brain contusions are mostly observed in car occupants. Since 2005 there has been a decrease in head injuries (−48%) for motorists, (−38%) for pedestrians, (−20%) for motorized two-wheelers. It is less pronounced for the cyclists (−11%). This noticeable decline among motorists is due to the road safety policies implemented in France since 2002. Cyclists are hardly affected by this decline due to their increase in numbers, due to the introduction of self-service bikes and due to the fact that wearing the helmet are not mandatory. Conclusion Head injuries have almost divided by two among motorists, but efforts need to be made for vulnerable road users. An effective strategy for all types of users must prevail. A first measure taken in France in March 2017, making the use of bicycle helmets mandatory for children under twelve, could be evaluated in the following years on the incidence of head trauma.