F Doricchi1, P Angelelli. 1. Centro Ricerche di Neuropsicologia, IRCCS S. Lucia Roma, Rome, Italy.
Abstract
BACKGROUND: Right-brain-damaged patients with left unilateral neglect are reported to misperceive the horizontal extension of contralesional stimuli as being shorter than that of ipsilesional stimuli. OBJECTIVE: To investigate the functional and anatomic correlates of horizontal space misrepresentation. METHODS: Eight right-brain-damaged patients with contralesional neglect and complete hemianopia (N+H+), nine right-brain-damaged patients with contralesional neglect and no visual field defect (N+H-), and five unilateral brain-damaged patients with contralesional complete hemianopia and no neglect (N-H+) reproduced a horizontal distance (10 cm) in the contralesional and ipsilesional hemispace. RESULTS: N+H+ patients overextended the distance contralesionally and underextended the same distance ipsilesionally. N+H- and N-H+ patients reproduced equivalent distances contralesionally and ipsilesionally. Compared with N+H- patients, N+H+ patients had a greater ipsilesional shift when bisecting horizontal lines; however, these two groups of patients had comparable neglect severity on multiple-item cancellation tasks. In the N+H+ group the area of maximal overlapping of the lesion was in the posterior cerebral lobes. CONCLUSION: Complete contralesional hemianopia after posterior brain damage is an important factor in determining misrepresentation of horizontal space in patients with left unilateral neglect.
BACKGROUND: Right-brain-damaged patients with left unilateral neglect are reported to misperceive the horizontal extension of contralesional stimuli as being shorter than that of ipsilesional stimuli. OBJECTIVE: To investigate the functional and anatomic correlates of horizontal space misrepresentation. METHODS: Eight right-brain-damaged patients with contralesional neglect and complete hemianopia (N+H+), nine right-brain-damaged patients with contralesional neglect and no visual field defect (N+H-), and five unilateral brain-damaged patients with contralesional complete hemianopia and no neglect (N-H+) reproduced a horizontal distance (10 cm) in the contralesional and ipsilesional hemispace. RESULTS: N+H+ patients overextended the distance contralesionally and underextended the same distance ipsilesionally. N+H- and N-H+ patients reproduced equivalent distances contralesionally and ipsilesionally. Compared with N+H- patients, N+H+ patients had a greater ipsilesional shift when bisecting horizontal lines; however, these two groups of patients had comparable neglect severity on multiple-item cancellation tasks. In the N+H+ group the area of maximal overlapping of the lesion was in the posterior cerebral lobes. CONCLUSION: Complete contralesional hemianopia after posterior brain damage is an important factor in determining misrepresentation of horizontal space in patients with left unilateral neglect.
Authors: H Chris Dijkerman; Robert D McIntosh; A David Milner; Yves Rossetti; Caroline Tilikete; Richard C Roberts Journal: Exp Brain Res Date: 2003-09-04 Impact factor: 1.972
Authors: M Urbanski; M Thiebaut de Schotten; S Rodrigo; C Oppenheim; E Touzé; J-F Méder; K Moreau; C Loeper-Jeny; B Dubois; P Bartolomeo Journal: Exp Brain Res Date: 2010-11-27 Impact factor: 1.972
Authors: Katia Andrade; Dalila Samri; Marie Sarazin; Leonardo C de Souza; Laurent Cohen; Michel Thiebaut de Schotten; Bruno Dubois; Paolo Bartolomeo Journal: BMC Neurol Date: 2010-08-10 Impact factor: 2.474