Affecting about two of every 1,000 people, absence seizures (formerly called ''petit mal'' seizures) are caused by abnormal and intense electrical activity in the brain.
Normally, the brain's nerve cells (neurons) communicate with one another by firing tiny electric signals. But with a seizure, these signals become abnormal. Seizures may affect an isolated part of the brain or may involve abnormal activity in the whole brain (called generalized seizures). Absence seizures are one form of generalized...
Epilepsy is a brain disorder that causes recurrent seizures (more than two). A seizure is caused by abnormal electrical activity in the brain.
Epilepsy may be the result of:
Irregularity in the wiring of the brain
Imbalance of neurotransmitters (chemical messengers in the brain)
Combination of these factors
In photosensitive epilepsy, genetics also plays a role.
About one in 100 people in the U.S. have epilepsy. About 3% to 5% of those people have photosensitive epilepsy.
Children and adolescents ages 7 to 19 are more likely to have photosensitive epilepsy. Girls are affected by the condition more often than boys. But boys tend to have more seizures. That's probably because they spend more time playing video games, a common seizure trigger.
What Causes Seizures in People With Photosensitive Epilepsy?
Seizure triggers vary from person to person. But some common triggers are:
Bright, contrasting patterns such as white bars against a black background
Flashing white light followed by darkness
Stimulating images that take up your complete field of vision, such as being very close to a TV screen
Certain colors, such as red and blue
Some specific examples of situations or events that can trigger seizures in people with photosensitive epilepsy are:
Nightclub and theater lights, including strobe lights
TV screens and computer monitors
Flashing lights on police cars, fire trucks, ambulances, and safety alarms
Visual effects in movies, TV shows, and video games
Malfunctioning fluorescent lights and moving escalators
Light viewed through a fast-moving ceiling fan
Sunlight viewed through slanted blinds or stair railings
Sun shining through tree leaves or reflecting off water
Bold, striped wallpaper and fabric
Cameras with multiple flashes or many cameras flashing at the same time
Also, people with photosensitive epilepsy may be at increased risk for a seizure if they are: