Analysis of photo-pattern sensitivity in patients with Pokemon-related symptoms.
This study was designed to analyze photo-pattern sensitivity in patients who developed acute neurologic symptoms associated with watching an animated television program, "Pokemon." The 18 patients (13 females and five males) underwent electroencephalograms and photo-pattern stimulation testing, including special stimulation test batteries (strobe-pattern test and cathode ray tube-pattern test). Photo-pattern sensitivity was confirmed in 16 patients with and without seizure episodes. The strobe-pattern test including a white flickering light test (with eyes open, closed, and open or closed), and the cathode ray tube-pattern test each induced a photo-paroxysmal response in more than 80% of patients. However, with the eyes closed only, as is common in Japan, the photo-paroxysmal response induction rate with a white flickering light stimulus was significantly lower (43%). In the cathode ray tube-pattern test, higher spatial frequencies produced higher rates of photo-paroxysmal response induction. It was demonstrated that underlying photo-pattern sensitivity is more accurately investigated by our method than by standard intermittent photic stimulation alone. By characterizing underlying photo-pattern sensitivity and identifying predisposing factors more precisely, we can develop better guidelines for prevention of a second "Pokemon" incident. According to the results of the present cathode ray tube-pattern test, pattern sensitivity (especially spatial resolution) appears to also be involved in Pokemon-related symptoms, in addition to chromatic sensitivity.
Funatsuka
Makoto
M
Department of Pediatrics, Tokyo Women's Medical University, Japan.
Fujita
Michinari
M
Shirakawa
Seigo
S
Oguni
Hirokazu
H
Osawa
Makiko
M
D000293:Adolescent; D000328:Adult; D002648:Child; D003626:Data Display; D004569:Electroencephalography; D004827:Epilepsy / Q000175:diagnosis* / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual; D010775:Photic Stimulation; D013690:Television; D014474:Unconsciousness / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control