By Saumya Joseph

(Reuters Health) – Flashing light effects that have become the norm for electronic dance music concerts could bring on epileptic seizures in young people who may not know they have a vulnerability, Dutch researchers say.

Young people flock to electronic dance music festivals that are popular for their loud music and intense stroboscopic light beams piercing the darkness. But those lights may be putting certain visitors at risk of injuries, hospitalization or other complications related to provoked seizures.

Lights strobing in the frequency range of 15-25 hertz, or cycles per second, are known for their potential to cause seizures, the study team writes in BMJ Open. This is especially true for people with photosensitive epilepsy, for whom exposure to flickering or flashing lights and patterns can trigger electrical disturbances in the brain.

After treating a 20-year-old man with no history of epilepsy, who was brought to the emergency department following a seizure at a nighttime dance party, Newel Salet of the VU Medical Center in Amsterdam and his colleagues set out to assess whether such cases happen more often than realized.

They analyzed data for more than 400,000 people who attended 28 electronic dance music concerts in The Netherlands in 2015, 60% of which were indoor or nighttime events.

During these concerts, medical assistance was provided more than 2,700 times. A total of 30 epileptic seizure cases were identified at nighttime concerts, while 9 seizure cases occurred during daytime events.

This difference in seizure events could be due to the light effects being far more intense in the dark than in well-lit daytime environments, Salet said.

“We expected somewhat more (seizures at night) than during the day, but not as much, maybe not three and a half times more,” he told Reuters Health by phone.

Although use of recreational drugs such as ecstasy – which has been associated with increased seizure risk – was also more likely during nighttime events, the proportion of seizure cases in which the drug was used was similar at both daytime and nighttime concerts, the researchers note.

Organizers of EDM festivals should warn visitors of the risk of seizures in situations where strobe lights are expected, as is done for some video games and movies that have intense light effects, said Dr. Ignacio Valencia of the Drexel University College of Medicine in Philadelphia. Valencia, who spoke on behalf of the American Epilepsy Society, wasn’t involved in the study.

Meanwhile, visitors with a history of photosensitive epilepsy should either avoid these events, or inform those accompanying them of their condition, as these seizures can occur very quickly, Salet said.

The researchers also recommend that visitors get enough sleep, avoid alcohol and recreational drugs, avoid standing too close to the stage and promptly move to a location away from the lights if they begin experiencing symptoms.

However, preventing seizures in patients who are light-sensitive can be tricky.

“If the lighting environment suddenly changes, someone may not have much time to reposition themselves if they are vulnerable,” said Dr. David Burkholder, a neurologist at the Mayo Clinic in Rochester, Minnesota, who wasn’t involved in the study.

“Nothing is completely reliable, but being aware of the potential for a problem, thinking ahead, and having a plan in place to reduce risk is important,” he said by email.

SOURCE: BMJ Open, online June 11, 2019.

(This story modifies para 10 to indicate that Dr. Valencia spoke on behalf of the American Epilepsy Society.)