Epilepsy Research (2009) 87, 213—222 journal homepage: www.elsevier.com/locate/epilepsyres Visual impairment at large eccentricity in participants treated by vigabatrin: Visual, attentional or recognition deficit? Fatima Naili a , Muriel Boucart a,* , Philippe Derambure b , Carl Arndt c a Lab. Neurosciences Fonctionnelles & Pathologies, Université Lille Nord de France, CNRS, France b Dept Neurophysiology, Lille University Hospital, France c Dept Ophtalmology, Reims University Hospital, France Received 26 June 2009; received in revised form 9 August 2009; accepted 4 September 2009 Available online 2 October 2009 KEYWORDS Epilepsy; Vigabatrin; Vision; Spatial attention; Object recognition; Eccentricity Summary A relationship between peripheral visual field loss and vigabatrin (VGB) has been reported in several studies but with inconsistent results. We investigated the level of visual processing at which the impairment occurs: attentional or cognitive (recognition) deficit. A simple reaction time task was used as a baseline condition. A spatial attention task measured the benefit and cost for the detection of a target appearing at a cued or at an uncued location. A rapid categorization task assessed object recognition. Performance was tested at eccentric- ities varying from 30 ◦ to 60 ◦ on a panoramic screen covering 180 ◦ . Participants were patients with epilepsy treated with VGB, patients treated with other drugs and healthy controls. In the VGB group 9 patients exhibited a mild visual field constriction. We observed a general slowing down of response times in participants treated by VGB, especially at 60 ◦ eccentricity but their performance remained above chance at large eccentricity in the most complex categorization task. The slowing down of visual processing at large eccentricity for flashed stimuli suggests that VGB treated patients might be impaired at detecting moving objects in the periphery and this may have consequences in behavioural tasks like driving. © 2009 Elsevier B.V. All rights reserved. ∗ Corresponding author at: CHRU Lille, Hôpital Roger Salengro, service EFV, Lab. Neurosciences Fonctionnelles & Pathologies, 59037 Lille, France. Tel.: +33 3 20 44 62 81. E-mail address: m-boucart@chru-lille.fr (M. Boucart). Introduction Vigabatrin (VGB) is a well-tolerated drug used for the treatment of partial seizures in adults and children. It is considered to be particularly effective in patients affected by drug-resistance epilepsy. The anticonvulsant properties of VGB increase in a dose-dependant man- ner. It was used until the late 1990s when isolated reports of concentric peripheral visual field loss and 0920-1211/$ — see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.eplepsyres.2009.09.003