Most traumatic brain injuries involving electric scooters occurred while the rider was intoxicated—restrictions have significantly reduced the number of accidents

The study analyzed all traumatic brain injuries related to e-scooter use that were treated in Helsinki between 2021 and 2023. The study included 184 patients, 29 of whom were diagnosed with an intracranial injury based on brain imaging. The study was published in the esteemed Journal of Neurology, Neurosurgery and Psychiatry.

“Although most of patients suffered only a mild brain injury, i.e., a concussion, some injuries were life-threatening and caused long-term disability,” says Dr. Pihla Tommiska.

The median age of the patients was 32 years, and 70 percent of were men. The most severe cases required neurosurgery and treatment in an intensive care unit.

Most patients were injured while intoxicated

Of the 141 patients for whom information on intoxication was available, 82 percent were under the influence of alcohol at the time of the accident.

In the cases of more severe traumatic brain injuries, intoxication was extremely common: 88 percent of those who suffered an intracranial injury were intoxicated at the time of the accident. Even among those who managed to avoid an intracranial injury, 79 percent were intoxicated.

Accidents most often occurred late in the evening or at night, and especially on weekends. Only about one in ten patients were wearing a helmet.

Restrictions have reduced the number of traumatic brain injuries

The study found that the incidence of traumatic brain injuries decreased significantly after restrictions on the use of electric scooters were introduced. In Helsinki, restrictions were placed on the nighttime use of public e-scooters in the fall of 2021.

“Before the restrictions were introduced, the incidence of traumatic brain injuries was 2.2 cases per 100,000 trips. "After the restrictions were implemented, that figure fell to 1.0. The results show that restrictions on riding e-scooters while intoxicated reduce the number of serious injuries," explains Dr. Henri Vasara.

About the study

The study was conducted in collaboration between HUS Emergency Medicine and Services, neurosurgery at the HUS Neurocenter, and the University of Helsinki. The study examined the period between 2021–2023.

Finland's electric scooter legislation was revised in June 2025. New legislation set the minimum age for riding e-scooters at 15, established a blood alcohol limit of 0.5 per mille, and provided a clearer recommendation regarding helmet use. There is currently no research data on the impact of these changes on accidents.

Further information:

Researcher, Specializing physician Pihla Tommiska, M.D.
pihla.tommiska@helsinki.fi

Researcher, Specializing physician Henri Vasara, M.D.
henri.vasara@helsinki.fi

Link to the publication: Characteristics and outcomes in electric scooter-related traumatic brain injuries in Helsinki

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