This is excerpted from the Epilepsy Foundation on Seizure Triggers:
“In contrast, reflex epilepsy is a condition in which seizures can be provoked by an external stimulus (flashing lights) or, occasionally, by an internal mental process (mathematical calculation). Reflex seizures are fairly predictable in response to specific stimuli, and may coexist with spontaneously occurring seizures. They are epileptic, not psychogenic, and may occur as either focal-onset or primary generalized seizures. An EEG response to repetitive light stimulation is called “photosensitivity,” and is seen in about 25 percent of individuals with primary generalized epilepsy.
Reflex epilepsy usually begins in childhood and may be outgrown by adulthood.
Triggers in pattern-sensitive epilepsy may include circles, stripes or other patterns, usually of high contrast. TV and electronic screen games have cause reflex seizures. This may be due to the flicker frequency(2) of the screen and distance from it, as well as images. European TV has a lower flicker frequency and is therefore more apt to trigger seizures. Individuals who experience their first seizure while playing electronic screen games(3) are found to be photosensitive.”
1. Emphasis is ours.
2. See Dr. Ciuffreda’s study on Critical Flicker Frequency for more information on this phenomenon.
3. See Wii game warning and migraine information.