By Robert Preidt, HealthDay Reporter

(HealthDay)

SUNDAY, Dec. 4, 2016 (HealthDay News) -- People with epilepsy who experienced longer seizures during a simulated driving test may face an increased risk for crashes while on the road, a new study suggests.

About 75 percent of people with epilepsy use medication to control their seizures and are able to drive. The remainder of patients typically keep a journal of seizures, noting how long they last, and doctors use that information to determine whether patients can drive safely, the study authors explained.

The new study included 16 people with epilepsy who used a driving simulator for between one to 10 hours, most for an average of three to four hours. In total, the patients had 20 seizures, seven of which resulted in "crashes."

The longer the seizure, the greater the chance of a "crash." Seizures lasted an average of 75 seconds among patients who crashed and 30 seconds among those who didn't crash.

The study was to be presented Sunday at the annual meeting of the American Epilepsy Society, in Houston.

"Our goal is to identify if certain types of seizures -- coming from a specific part of the brain or causing a particular brain wave pattern -- are more likely to lead to a crash. That information could then be used by doctors to objectively determine who can safely drive and who should not," said study author Dr. Hal Blumenfeld, director of the Yale Clinical Neuroscience Imaging Center, in New Haven, Conn.

Blumenthal, who is also a professor of neurology, neuroscience and neurosurgery at Yale, added that it isn't clear why people who have longer seizures are more likely to crash.

"It's going to take a lot more data to come up with a reliable way of predicting which people with epilepsy should drive and which should not," Blumenfeld said in a news release from the epilepsy society.

"We want to unearth more detail, to learn if there are people with epilepsy who are driving who shouldn't be, as well those who aren't driving who can safely drive," he said.

More information

The U.S. National Institute of Neurological Disorders and Stroke has more on epilepsy.