Frequency and characteristics of traumatic brain injury in restrained drivers involved in road traffic accidents

Background: While seatbelt is an important device protecting drivers from traumatic brain injury (TBI), it has rarely been reported how often and in what circumstances restrained drivers sustain TBI after road traffic accident (RTA). Whole-body computed tomography (WBCT) for blunt trauma patients may provide a unique opportunity to investigate the frequency and characteristics of TBI sustained by restrained drivers. Methods: A single-center, retrospective observational study was conducted using prospectively acquired data. Between January 2013 and December 2017, 409 restrained drivers (284 men/125 women, mean age of 45.0 +/- 19.1years) whose vehicle had been severely damaged in RTAs underwent WBCT for evaluation of injuries. Multivariate regression analysis was performed to identify variables predictive of TBI. Influence of collision patterns (frontal, lateral or rollover) on the frequency and severity of TBI was evaluated. Relationship between collision patterns and CT findings was also reviewed. Results: Thirty-one restrained drivers (7.6%) sustained TBI after RTA. The distribution of Glasgow Coma Scale (GCS) scores among the 31 drivers was 15 in 9, 13-14 in 9, 9-12 in 4, and <8 in 9, indicating that the majority of TBIs were classifiable as mild. The frequency of TBI in alert and oriented drivers, i.e., those with a GCS score of 15, was 2.9%. Multivariate regression analysis showed that both altered mental status (OR, 4.933; 95% CI, 1.135-21.431) and loss of consciousness (OR, 6.492; 95% CI, 1.669-25.249) were associated with TBI. The frequency of TBI tended to be higher in drivers with rollover collision than those with frontal collision (6 vs. 13%, p=0.07). Interhemispheric acute subdural hematoma and subcortical petechial hemorrhage seemed to be characteristic CT findings in drivers with frontal and lateral collision, respectively. Conclusions: The key finding of this study, i.e., that (1) TBI was observed in 7.6% of restrained drivers with severe vehicular damage, may provide useful information to neurosurgeons who take care of RTA victims. The majority of the TBIs were mild without need for neurosurgical intervention. While association may exist between type of collision and type of brain injury, further studies with prospective design are warranted.