Risks of seizure with fatal traffic crash at wheel in people with epilepsy

The Japanese authorities require a 2-year seizure-free period for a driver's license in people with epilepsy. To evaluate the stringency of the criteria, we calculated the risk of fatal traffic crashes by epileptic seizure and compared that to the risk of fatal traffic crashes among the general population.

Nation-wide questionnaire surveys to physicians and their patients with epilepsy were conducted to determine the rate of seizure recurrence after given seizure-free periods, average driving time and the rate of traffic crashes by epileptic seizures. The risk of fatal traffic crashes by epileptic seizures was calculated using the method proposed by the Driving License Committee of the EU. The risk of fatal traffic crashes among subgroups of the general population was calculated using the national statistics available.

Valid answers were obtained from a total of 548 patients of 138 epilepsy-specialists and 102 non epilepsy-specialist physicians. The relative risks of fatal traffic crashes in people with epilepsy with 1-year and 2-year seizure-free periods were 1.22 and 1.15, compared to the general population, while the ones in males in their twenties, people aged 60 and over, people aged 65 and over, and people aged 75 and over among the general population were 1.71, 1.31, 1.52 and 2.69, respectively.

The risk of fatal traffic crashes in people with epilepsy for 1-year and 2-year seizure-free periods was estimated to be lower than that of some age groups in the general population. The increased risk in 1-year seizure freedom from that in 2-year seizure freedom was relatively small.