Characteristics and outcomes in electric scooter-related traumatic brain injuries in Helsinki

BACKGROUND: Electric scooter (e-scooter)-related traumatic brain injuries (TBIs) have become increasingly common with the adoption of shared e-scooters. Previous studies have focused on severe injuries. We aimed to describe the characteristics and outcomes of e-scooter-related TBIs. METHODS: This retrospective cohort study included all e-scooter-related TBIs presenting to all three adult emergency departments in Helsinki during 2021-2023. Data were obtained based on a keyword search from the hospital database. TBI cases were identified using the International Classification of Diseases 10th Revision diagnostic codes and manually verified. All brain imaging reports were reviewed, and imaging-positive scans were re-evaluated. RESULTS: A total of 184 patients with e-scooter-related TBIs were included. The mean age was 32 years, and 128 (70%) were male. The incidence of TBIs was 1.3 per 100 000 e-scooter trips, decreasing from 2.2 to 1.0 per 100 000 trips after implementation of usage restrictions. Most injuries occurred during night-time hours, with Saturdays and Sundays being the most common days. Alcohol intoxication was documented in 82% of patients, while helmet use was reported in 9%. Concussion was the most common diagnosis (84%). 29 patients (16%) had intracranial findings on brain imaging, most commonly cerebral contusions, traumatic subarachnoid haemorrhages, subdural haematomas and diffuse axonal injuries. Four patients required operative treatment, including three who underwent neurosurgical procedures. CONCLUSIONS: Alcohol intoxication is highly prevalent among patients with e-scooter-related TBIs and represents an important modifiable risk factor for these injuries. Stricter enforcement against riding under the influence of alcohol may help reduce e-scooter-related TBI incidence and severity.