Seizure-related injuries common: Head wounds and drowning risk top list of dangers

Each year, seizures cause injuries in about 1 in 10 people with epilepsy, according to the results of an Australian study.

Researchers surveyed 819 people who were part of a community-based registry in Tasmania. They were asked about seizure-related injuries over their lifetime and during the previous 12 months.

Of those surveyed, 43.1% had a lifetime history of at least one injury, and 9.9% had an injury in the previous 12 months.

Many studies of seizure-related injuries are hospital based and can show high injury rates, noted Ley Sander, professor of neurology at University College London and head of the Department of Experimental and Clinical Epilepsy, who was not involved in the study. “People see those studies and say ‘Oh, those injuries don’t happen in real life.’ This study shows that they do, and that having active epilepsy is a risk factor for injury.”

“We know that morbidity from seizure-related injuries is common, but to my knowledge there have been very few studies trying to map this,” said Sander. “This study is quite robust because of the methodology.”

Seizure frequency was correlated with risk of injury. That might not seem surprising, but it’s a key finding, said senior study author Wendyl D’Souza, epileptologist at St. Vincent’s Hospital, Melbourne and associate professor at University of Melbourne Medical School.

“We found that having even just one seizure a year is a risk for injury,” he said. “I think that reflects the unpredictability of seizures. If you have frequent seizures, you often restrict your activities and you’re mindful of getting in the pool or playing sports. But if [seizures happen] once a year, you’ve maybe lulled yourself into thinking that you’re okay.”

Said Sander, “This study shows that you need to be seizure free to be safe. A 50% reduction in seizure frequency might be good as a regulatory outcome, but it’s not good for patients.” 

After adjusting for seizure frequency, three risk factors remained:

• Impaired awareness during seizures
• Convulsive cluster seizures
• Having seizures only when awake (versus during sleep)

Head injuries were common, with a lifetime incidence of 21.6% and recent incidence of 3.9%. About 1 in 4 head injuries required stitches.

Other types of injuries included immersion in water—while bathing, showering or swimming—as well as burns, cuts, broken bones and dental injuries. Eighteen percent of the injuries were reported as occurring in public, and about 60% in the home. 

“The study showed that water is a big risk,” said D’Souza. “And importantly, it reinforced that drowning risk happens at home.”

The risk of drowning in people with epilepsy is 15 to 19 times greater than that of the general population. “In the UK there are between 80 and 120 bathtub drownings every year, and the great majority of those are people with epilepsy,” said Sander. He suggests simple safety measures, such as making someone else in the house aware of where you are and keeping the bathroom door unlocked.

Eleven percent of participants reported ever having a seizure while driving; however, only 1 in 10 participants chose to answer driving-related questions. The authors statistically addressed the missing data and found that the non-responses had a minimal effect on the results.

The study did not find that people who had seizure warnings (sometimes called auras) were at lower risk of injury.

“Patients think if they have a warning of a seizure, they’ll be okay,” said D’Souza. “But if you have a warning that usually means you’re having a lot of seizures, and not all of them come with a warning, and patients don’t know they’re having them. It’s sad and hard to reinforce to patients that they have seizures they don’t even know about, and that puts them at risk [for injury].”

Compared to the general population, people with epilepsy have two to three times the risk of death, which includes death from seizure-related injury. In many countries, seizure related injuries and drownings are major contributors to the death rate.  This paper emphasizes the importance of reviewing safety issues to help patients minimize the risk for injuries from seizures.

The study was published online Feb 5 in Epilepsia.