I haven't seen any of the Twilight movies but many people have and it seems there are certain scenes in the movie that are triggering seizures in some epileptic patients. Twilight isn't the only movie that has had this effect on those who suffer from seizures.

Movies in the past like Avatar, 127 Hours, and Cloverfield have had bad side effects on movie goers, including death. It seems some movies can cause over activity in some brain cells or over stimulation/excitment of the heart causing medical problems.

The current Twilight movie "Breaking Dawn" is causing epileptic seizures. Those who suffer from the affliction are passing out during the birth scene. This scene has lots of flashing lights and effects and colors, especially red, can trigger the seizures.

Most of the time our brains have chaotic activity going on but in patients suffering from epilepsy when seeing strobbing lights it causes those normally chaotic activities to synchronize and cause the seizure.

So just be aware if you go see the movie and you suffer from this condition, you might want to look away from the screen during this particular scene.