Pocket Monsters attacks Japanese children via media

Physiology of Human Photosensitivity

Human epileptic photosensitivity has been studied in several ways. (a) Visual stimulation that resembles the stimulation normally responsible for seizures, such as that from televisions or videogames, both of which typically use cathode ray tubes in which the display is created in a flickering pattern. Such stimulation is often rendered yet more epileptogenic by programmes with content that also involves flashing or patterned material. (b) Elementary visual stimuli that enable inferences to be drawn concerning the physiological trigger mechanisms. The topographic distribution of epileptiform EEG activity in response to such stimuli has complemented this approach, leading to the inference that the trigger is cortical and requires sychronised mass action of neurons. (c) Stimuli that avoid paroxysmal EEG activity and permit an investigation of the subepileptic response to visual stimuli, using the evoked potential. This has revealed abnormalities in the cortical mechanisms that control the response to strong visual stimulation.

A comparison survey of seizures and other symptoms of Pokemon phenomenon

On 16 December 1997, many Japanese children developed neurologic problems while watching the animated television series Pokemon. This study included children who visited the outpatient departments of 14 pediatric clinics for other reasons within 2 months after this incident. Volunteering children and parents or guardians were asked to complete questionnaires. We obtained 1,373 replies (including 800 males, 558 females, and 15 children without information on sex; mean age, 6.8 +/- 3.5 years). The majority of children included in this study (80%) watched this program, and 67 (6.1%; 40 males, 27 females) were affected by the program. There were 10 patients with seizures (0.9%; four males and six females). Fifty-seven patients developed other symptoms. Compared with nonaffected children, significantly more affected children reported that they concentrated on watching this program, watched it at a short distance from the screen, and did not watch this program in a brightly lit room. Seizures tended to occur in older children (average = 10.8 years) and in children with a high rate of familial histories of seizures. Symptoms other than seizures occurred more frequently, and autonomic and psychologic factors, such as motion sickness, could be considered possible mechanisms. Children who developed symptoms seemed to have problems in viewing conditions.

Chromatic sensitive epilepsy: a variant of photosensitive epilepsy

We herein report 4 Japanese children who suffered epileptic seizures while watching a popular animated TV program. They showed a photoparoxysmal response that is more frequently observed in response to rapid color (blue/red) frame changes than monochromatic ones. These patients were all considered to have photosensitive epilepsy; however, chromatic sensitivity also plays an important role in the generation of such seizures.