A new study published in the medical journal of the American Academy of Neurology has found that 5% of people with focal epilepsy had a seizure while driving prior to being diagnosed. Focal epilepsy is responsible for more than half of all cases of epilepsy and is characterised by recurring seizures which affect one half of the brain.
The study identified 447 people with focal epilepsy and found that 23 of them, or 5%, experienced one or more seizures while driving prior to their diagnosis. Of the 23, 30% experienced more than one seizure while driving and for 26% this was their first-ever seizure. The average time from experiencing a first seizure to experiencing a seizure while driving was 304 days and the average time between a person’s first seizure while driving to being diagnosed with epilepsy was 64 days.
People who were employed had a four times greater risk of experiencing a seizure while driving prior to diagnosis than those who were not employed. Additionally, people who experienced non-motor seizures, where movement stops and a person may simply stare, had a nearly five times greater risk of experiencing a seizure while driving prior to diagnosis than those who had a motor seizure, which can include sustained jerking movements or muscles becoming weak or alternately becoming rigid.
The consequences of seizures while driving can be severe. In the study, there were 19 motor vehicle accidents and 11 hospitalisations for injuries ranging from a tongue bite and a dislocated thumb to a near drowning.
The authors of the study hope that their results will help inform how to diagnose people sooner, with a goal of lowering the number of prediagnosis seizures on the road.
One limitation of the research was that some seizure history for participants was self-reported, which may have led to underreporting of the number of seizures while driving. In addition, the study was small and examined only one type of epilepsy, so future studies are needed in larger groups of people.
The study concludes by stating that considering that the United States has a population of just over 200 million people between ages 16 and 64, and considering the annual incidence of epilepsy, there are roughly 126,180 driving-age people in the country diagnosed with epilepsy each year. From their study, the authors estimate nearly 6,500 people per year may experience prediagnosis seizures while driving in the United States alone, leading to nearly 4,000 possible motor vehicle accidents and over 2,200 hospitalisations. Much of this may be preventable by earlier diagnosis.
