Driving Simulation in Epilepsy and Sleep Disorders

Drivers with sleep disorders, such as obstructive sleep apnea (OSA), have an increased crash risk that can be difficult to predict in individual drivers. Epileptics may also have an increased risk, although the extent of that risk is not completely defined. Because seizures are intermittent events, and impairment from sleepiness varies based upon a variety of factors, determining crash risk is difficult in these patient populations. Driving simulators offer an opportunity to study drivers with episodic impairment of function due to sleep disorders or seizures in a safe, controlled environment. The addition of divided attention tasks and physiological measures, such as the electroencephalogram (EEG), may enhance the ability to detect dangerous driving behaviors. Studies with driving simulators show that drivers with OSA and narcolepsy perform worse than those without neurological and sleep disorders, and their performance improves with treatment. Few data are available on drivers with epilepsy, although some preliminary studies have shown deteriorated performance due to medications and EEG-defined “subclinical” seizures. Studies of drivers with sleep disorders typically use scenarios that are monotonous, with few obstacles. Some have incorporated tests of divided attention. Standard deviation of lane position (SDLP) is the most frequently used dependent variable to differentiate drivers with sleep disorders from normal controls, although other measures, such as crashes or off-road events are also used. Little is known about appropriate scenarios and dependent variables in epileptic drivers. All currently available simulators have the scenario development tools and data-recording capabilities required to perform the necessary assessments. However, standardization of these procedures does not exist at present.