Seizures occurring while driving in patients with and without diagnosis of epilepsy: Frequency and association with automobile accidents.

Seizure may occur during any human activity, including driving. The objectives of this study were to report the frequency of seizure occurring while driving, clarify patient characteristics and analyze the behavioral patterns of drivers afflicted by seizure. A single-center, retrospective study was conducted using prospectively acquired data. Data of 658 adult seizure patients who visited our emergency department between January 2011 and December 2016 were used for analysis, focusing on daily activities immediately before seizure. Nineteen of the 658 patients (2.9%) sustained seizure while driving. The 658 patients were dichotomized on the basis of whether he or she had been diagnosed with epileptic seizure (ES). Seven of the 307 patients with ES vs. 12 of the 351 patients without ES sustained seizure while driving. The frequencies did not differ significantly between the two groups (2.3% vs. 3.4%, p = 0.49). Structural lesions on brain imaging studies were found in 6 of the 12 patients without ES (50%). Sixteen of the 19 patients (84%) caused automobile accidents after seizure. Among the 7 patients with ES, antiepileptic drugs had not been prescribed in 3 (43%). Although seizures occurring while driving have been studied extensively, most researchers focused on patients with ES. This study was unique because it focused on patients without ES, and the current findings that seizures in patients without ES outnumbered seizures in those with ES may be informative to clinical neuroscientists and emergency physicians. Prospective studies are expected to identify individuals at risk for first seizure occurring while driving.