title: Topographic Analysis of Electroencephalographic Changes during Photic Driving Responses in Patients with Migraine.
abstract: OBJECTIVE
  Migraineurs demonstrate abnormal information processing such as photic hypersensitivity. The photic driving response to photic stimulation (PS) is a reaction to the visual stimulation of electroencephalography (EEG). Both the photic driving response and photic hypersensitivity appear during light stimulation. We considered that evaluation of a migraineur's photic driving response may help to elucidate the mechanism of the migraineur's sensitive condition. Our study aimed to investigate EEG photic driving responses with a source-localizing method.
  
  
  METHODS
  We recorded spontaneous resting EEG with eyes closed from 20 electrodes on the scalp during the interictal phase. After recording, each PS was separately selected. We also analyzed EEG by fast Fourier transform and observed the spectrum frequency peaks and topographies in response to PS.
  
  
  RESULTS
  The photic driving response could be observed at a flashing rate of >15 Hz. Patients with photic hypersensitivity tended to show more photic driving regardless of the migraine subtype. Moreover, in topographies, their activated areas were shifted anteriorly from fundamental driving to harmonic driving for each photic frequency. This anterior shift was more evident with a longer duration of illness, although no significant differences were seen between migraine subtypes. The global field power value had a positive correlation with the duration of illness.
  
  
  CONCLUSIONS
  Photic hypersensitivity and photic driving responses were increased in migraineurs. Photic hypersensitivity might result in sensitization of the limbic system. © 2015 S. Karger AG, Basel.
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Takashima
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Kimoto
authors.forename: Yuka
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Koichi
authors.initials: K
authors.lastname: Hirata