SEATTLE – Auras don’t keep epilepsy patients safe while driving, according to a Yale University review of 215 medically-refractory epilepsy patients who had seizures behind the wheel.
Patients who have auras before their seizures are just as likely to get into accidents as are those who do not. “Our findings question the assumed protective benefit of reliable auras against motor vehicle accidents,” said Dr. Vineet Punia, a fellow in clinical neurophysiology, EEG, and epilepsy at the Cleveland Clinic.
It’s widely assumed that auras give patients enough time to pull off the road before a seizure. Many states have codified that belief into their driving laws based on advice from the American Academy of Neurology and American Epilepsy Society to use “consistent and prolonged auras” as a favorable factor when deciding if epilepsy patients should be licensed to drive (Epilepsia 1994;35:696-705).
That assumption has led to “a false sense of security,” Dr. Punia said at the annual meeting of the American Epilepsy Society. Even when they last more than a minute, “auras do not decrease the risk of motor vehicle accidents. We need to educate” people about this, he said, and, perhaps, rethink the laws.
He and his team looked for differences between the 141 patients who said their seizures caused car accidents, and the 74 who said they did not. The patients in the study were culled from the Multicenter Study of Epilepsy Surgery database.
If auras kept patients safe, the team reasoned that they would be more common in the accident-free group, but that’s not what they found. About 66% of the accident-free group reported having reliable auras before their attacks, the same as in the group that had seizure-related crashes. About 20% in both groups estimated that their auras lasted more than a minute, and about 41% in both thought that their auras were almost always long enough to prevent accidents.
“The presence of a reliable aura did not differ between the two groups. Having a longer aura did not prevent accidents. This would definitely affect how I counsel patients who want to drive,” Dr. Punia said.
The two groups were evenly matched. In both, about 86% had temporal lobe epilepsy; the majority had complex partial seizures (CPS); 45% were women; and the average age was 40 years.
There were a few factors that increased the odds of being involved in a motor vehicle accident, including having a history of CPS (odds ratio, 2.83; 95% confidence interval, 1.14-7.09; P = .029), at least one CPS per month in the last 3 months (OR, 2.52; 95% CI, 1.22-5.21; P = .01), and postictal periods of a minute or more (OR, 2.53; 95% CI, 1.04-6.19; P = .05) .
“CPS and longer postictal state are the most salient features of seizures” that increase the risk of accidents, suggesting that “impairment of consciousness may be a key factor,” they said.
The work was funded internally, and the investigators said they have no relevant industry disclosures.