title: Vertical saccades in dyslexic children.
abstract: Vertical saccades have never been studied in dyslexic children. We examined vertical visually guided saccades in fifty-six dyslexic children (mean age: 10.5±2.56 years old) and fifty-six age matched non dyslexic children (mean age: 10.3±1.74 years old). Binocular eye movements were recorded using an infrared video-oculography system (mobileEBT®, e(ye)BRAIN). Dyslexic children showed significantly longer latency than the non dyslexic group, also the occurrence of anticipatory and express saccades was more important in dyslexic than in non dyslexic children. The gain and the mean velocity values were significantly smaller in dyslexic than in non dyslexic children. Finally, the up-down asymmetry reported in normal population for the gain and the velocity of vertical saccades was observed in dyslexic children and interestingly, dyslexic children also reported an up-down asymmetry for the mean latency. Taken together all these findings suggested impairment in cortical areas responsible of vertical saccades performance and also at peripheral level of the extra-ocular oblique muscles; moreover, a visuo-attentionnal bias could explain the up-down asymmetry reported for the vertical saccade triggering.
authors.affiliation: UMR 1141 INSERM-Université Paris 7, Hôpital Robert Debré, 48 Bl Sérurier, 75019 Paris, France. Electronic address: tiadibikuyami@yahoo.fr.
authors.forename: Aimé
authors.initials: A
authors.lastname: Tiadi
authors.affiliation: e(ye) Brain, 1 bis rue Jean le Galleu, 94200, Ivry sur Seine, France.
authors.forename: Magali
authors.initials: M
authors.lastname: Seassau
authors.affiliation: Service d'Ophtalmologie, Hôpital Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bui-Quoc
authors.affiliation: Service de Psychopathologie de l'enfant et de l'adolescent, Hôpital Robert Debré, 48 Bl Sérurier, 75019 Paris, France.
authors.forename: Christophe-Loïc
authors.initials: CL
authors.lastname: Gerard
authors.affiliation: UMR 1141 INSERM-Université Paris 7, Hôpital Robert Debré, 48 Bl Sérurier, 75019 Paris, France.
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Bucci
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D004410:Dyslexia / Q000503:physiopathology*; D053483:Eye Movement Measurements; D006801:Humans; D012438:Saccades / Q000502:physiology*
keywords: Children; Dyslexia; Vertical saccades