At 6:30 PM on Tuesday, December 16, 1997, Pokémon episode 38, entitled "Dennou Senshi Porigon," meaning "Computer Warrior Polygon," aired in Japan on TV Tokyo. The program was popular at the time of its broadcast and held the highest ratings for its time slot, with an average market share of about 15%. In the episode, Pikachu and its human friends Satoshi, Kasumi, and Takeshi have an adventure that leads them inside a computer. About 20 minutes into the program, the group encounters a fighter named Polygon. A battle ensues, during which Pikachu uses its electric powers to stop a "virus bomb." The animators depict Pikachu's electric attack with a quick series of flashing lights.
In all, millions watched the program. In one city, Toyohashi, more than 70% of the 24,000 elementary school students and 35% of the 13,000 junior high school students watched the program, for a total of more than 21,000 viewers in Toyohashi alone. In Tokyo, the Kawasaki education board investigated all public kindergartens and primary and middle schools in the area and found that 50,714 students, or 55% of the children, watched the episode.
At 6:51 PM, the flashing lights of Pikachu's "attack" appeared on television screens. By 7:30 PM, according to Japan's Fire-Defense Agency, 618 children had been taken to hospitals complaining of various symptoms. News of the illnesses spread rapidly throughout Japan and became the subject of media reports later that evening. During the coverage, several stations replayed the flashing sequence, whereupon even more children fell ill and sought medical attention. The number affected by this "second wave" is unknown. Reported symptoms included convulsions, altered levels of consciousness, headaches, breathlessness, nausea, vomiting, blurred vision, and general malaise.[6,7,8]
South Med J. 2001;94(2) © 2001 Lippincott Williams & Wilkins
Cite this: Pokemon Contagion: Photosensitive Epilepsy or Mass Psychogenic Illness? - Medscape - Feb 01, 2001.