Abstract
At the Canadian Concussion Centre, we treated 136 patients from 2000 to 2020 who sustained concussion plus persisting concussion symptoms (C+PCS) as motor vehicle occupants involved in motor vehicle crashes (MVCs). This center specializes in the treatment of patients with C+PCS. The objective of the present study was to identify strategies for preventing concussion among vehicle occupants involved in MVC. Indeed, this is the first study focused on C+PCS in MVC occupants, and our main purpose was to evaluate the effectiveness of onboard concussion prevention strategies. In this retrospective, consecutive cohort of 136 patients with C+PCS, we examined the patients' demographic and injury features in relation to the nature of the MVC including speed, direction of impact, and availability, deployment, and effectiveness of onboard occupant safety measures including seatbelts, head restraints, and airbags. The most frequent combination of factors was a belted female driver of an automobile struck from behind by another automobile. Surprisingly, the entire patient cohort comprised more females (69.1%) than males (30.9%), and rear-end collision was the most common type in females. Most injured occupants of both sexes were wearing seatbelts, but only a minority of the crashes caused airbag deployment. The seven most common symptoms were headache (84.6%), anxiety (72.8%), sensitivity to light (70.6%), memory problems (69.9%), sensitivity to noise (66.2%), irritability (56.6%), and depression (55.9%). Whiplash was a frequent associated injury in both sexes. Complete recovery from C+PCS was rare, and most patients with known follow-up continued to suffer from persisting symptoms for months to years. The median symptom duration for all 136 patients was 30.0 months (interquartile range: 16.8-56.0 months). Based on these findings, we conclude that females are indeed vulnerable road users with respect to C+PCS, and our literature search showed that there had been some previous evidence of increased injury risk of other injuries in female occupants. We recommend that additional prevention strategies are required to reduce the post-crash acceleration-deceleration "bobble-head" movement of the head on trunk causing both concussion and whiplash as has been accomplished in auto racing. Also, these prevention measures must be investigated in crash studies that include low-to-high speed rear-end collisions using anthropometrically appropriate models of male and female occupants reflecting the range of sizes of both sexes. There is a need for more concussion brain injury prevention research focusing on the vulnerability of female occupants, which has not been sufficiently addressed even though the deficiency was identified many years ago. The sex inequity of current onboard motor vehicle concussion brain injury prevention measures especially with respect to females should be addressed by governments and the automobile and insurance industries.