Q: Please reference the effects of strobe lights on seizures.
The long-term care facility that I'm involved with ( as a physical therapist and a seizure patient) has recently installed strobes as part of their fire safety system. I would like to have some information to give to the maintainance department regarding the possible effects on people with seizure disorders.
Any help would be appreciated.
A: A small minority of persons with epilepsy have photosensitivity, which means that flashing or flickering lights may trigger a seizure, which is usually a tonic-clonic (convulsive) seizure. On EEG, this response is seen especially at frequencies of 10-20 flashes per second. If you have had an EEG, you might have noticed that they will use a strobe during the recording to see if you have photosensitivity. The most common sources of flashing light that would trigger a seizure include televisions (hence, the association with video-games). We have also seen instances of seizures triggered by flashing light from by waving of hands in front of the face, sun passing through a picket fence while riding in a car, reflections off a running stream of water, flames from a fire, and of course, disco strobes. In most cases, this type of seizure is very sensitive to valproate (Depakene, Depakote).
Usually the fire alarm strobes flash at a slow rate, for example about 1 flash per second. They are intended to alert persons who may be deaf or hard of hearing. At a very slow frequency, the light is probably not that seizure provoking. However, you may wish to contact your maintenence department about this.
Dean K. Naritoku, M.D.
Center for Epilepsy
Southern IL University
Springfield, IL