ORIGINAL COMMUNICATION REM sleep behaviour disorder and visuoperceptive dysfunction: a disorder of the ventral visual stream? Ana Marques • Kathy Dujardin • Muriel Boucart • Delphine Pins • Marie Delliaux • Luc Defebvre • Philippe Derambure • Christelle Monaca Received: 24 August 2009 / Accepted: 11 September 2009 / Published online: 30 September 2009 Ó Springer-Verlag 2009 Abstract In idiopathic rapid eye movement sleep behaviour disorder (RBD), an association with visuoper- ceptive disorders has been described. However, such an association has not been clearly established in RBD sec- ondary to Parkinson’s disease (PD). We compared visuo- perceptive function in four groups of non-demented patients (parkinsonian patients with or without RBD, patients with idiopathic RBD and control participants) via a procedure enabling the analysis of the various components of visual information processing and in order to answer the following question: is RBD associated with visuoperceptive and/or attentional disorders in PD and, if so, where is the dys- function located along the visual pathway? Sensorial aspects of visual information were evaluated using a con- trast sensitivity test, perceptual aspects were assessed using a contour-based object identification test and visual atten- tion was measured in an attentional capture paradigm. The diagnosis of RBD was confirmed by polysomnography. We observed a higher object identification threshold (OIT) (1) in PD patients with RBD compared with PD patients without RBD and with controls and (2) in idiopathic RBD patients compared with controls. There were no significant OIT differences between PD patients with RBD and idio- pathic RBD patients or between PD patients without RBD and controls. We did not find any significant inter-group differences in any of the other visuoperceptive tests. RBD, idiopathic or secondary to PD, is associated with perceptual closure dysfunction. Our results suggest that this perceptual dysfunction is specifically associated with RBD and may be related to a non-dopaminergic impairment. Keywords REM sleep behaviour disorder Á Parkinson’s disease Á Visuoperception Á Perceptual closure Introduction Rapid eye movement (REM) sleep behaviour disorder (RBD) is a parasomnia characterised by loss of normal skeletal muscle atonia during REM sleep, which then enables dream mentation to be acted out. Behaviour is fre- quently elaborate, violent (screaming, punching, grasping, kicking, etc.) and potentially harmful for the patient him/ herself and/or their bedpartner [1]. Polysomnographic recording reveals loss of muscle atonia during more than 20% of the periods of REM sleep and is required to confirm the diagnosis [2]. RBD affects mainly men (sex ratio: 8/1) over 50 and its prevalence in the general population is about 0.5% [3, 4]. RBD may be either idiopathic or secondary to neurodegenerative diseases (particularly alpha-synuclein- opathies) [5, 6]. In its idiopathic form, RBD is frequently associated with cognitive impairment in general and visu- operceptive disorders in particular [7–11]. Ferini-Strambi A. Marques Á P. Derambure Á C. Monaca (&) Service de Neurophysiologie Clinique, Unite ´ des troubles de la veille et du sommeil, EA 2683, IFR 114, Ho ˆpital Roger Salengro, CHRU de Lille, Lille cedex 59037, France e-mail: c-monaca@chru-lille.fr A. Marques e-mail: anamarques6@yahoo.fr K. Dujardin Á M. Delliaux Á L. Defebvre Service de Pathologie du Mouvement, EA 2683, IFR 114, Ho ˆpital Roger Salengro, CHRU Lille, Lille cedex 59037, France M. Boucart Á D. Pins Laboratoire Neurosciences Fonctionnelles et Pathologies, CNRS UMR 8160, IFR 114, Universite ´ Lille 2, CHRU Lille, Lille cedex 59037, France 123 J Neurol (2010) 257:383–391 DOI 10.1007/s00415-009-5328-7