title: Typical absence seizures triggered by photosensitivity.
abstract: OBJECTIVE
  To describe the characteristics of patients with typical absence seizures (TASs), consistently triggered by photosensitivity.
  
  
  METHODS
  Consecutive patients having TAS induced by intermittent photic stimulation were included in the study. All clinical parameters, EEG, and video-EEG data were assessed during the long-term follow-up. Statistical analyses were performed with SPSS 10.0 software.
  
  
  RESULTS
  Nine female and two male patients with a mean age at onset of 14 +/- 5.9 years (range, 7-27 years) and with a mean follow-up of 9 +/- 7.56 years had photosensitive TASs. They constituted 7.64% of absence epilepsies and 0.4% of all patients seen in our tertiary center. The seizures were usually subtle and had a reported frequency of 1 to 9 times daily. Seven patients were clinically photosensitive and reported that some of their TASs were induced by photic stimuli in daily life. All patients also had spontaneous TASs, and four of them had generalized tonic-clonic seizures. EEG results did not show any distinctive features when compared with those of other cases with TASs. Remission could not be achieved in five patients with antiepileptic drug treatments, and we always observed relapses after drug discontinuation or dose reduction in the remaining six cases in remission. Spontaneous remission did not occur even in the five patients older than 30 years.
  
  
  CONCLUSIONS
  TASs triggered by photosensitivity are a rare and heterogeneous clinical condition with a marked female preponderance. It is notable that TASs do not remit in these cases.
authors.affiliation: Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey. baykanb@istanbul.edu.tr
authors.forename: Betül
authors.initials: B
authors.lastname: Baykan
authors.forename: Zeliha
authors.initials: Z
authors.lastname: Matur
authors.forename: Candan
authors.initials: C
authors.lastname: Gürses
authors.forename: Ebru
authors.initials: E
authors.lastname: Aykutlu
authors.forename: Ayşen
authors.initials: A
authors.lastname: Gökyiğit
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000553:Ambulatory Care; D002648:Child; D004569:Electroencephalography / Q000706:statistics & numerical data; D004831:Epilepsies, Myoclonic / Q000175:diagnosis / Q000209:etiology; D004832:Epilepsy, Absence / Q000175:diagnosis* / Q000209:etiology; D020195:Epilepsy, Reflex / Q000175:diagnosis* / Q000209:etiology; D004830:Epilepsy, Tonic-Clonic / Q000175:diagnosis / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000009:adverse effects; D011446:Prospective Studies; D014743:Videotape Recording