SPATIAL CHARACTERISTICS OF CEREBRAL POLYOPIA - A CASE-STUDY

A 41-year-old woman showed bilateral monocular polyopia and an incompl ete, right-sided homonymous hemianopia following bilateral cerebral st rokes confirmed by neuroimaging. She was tested with briefly-presented visual stimuli to determine whether her polyopic images varied with v isual field position of stimuli which evoked them. Stimuli close to he r scotoma elicited polyopic images at shorter latency and higher proba bility than did stimuli more distant from it. RS could maintain stable fixation on small stimuli, suggesting that eye movements were not res ponsible for her polyopia. We discuss the possibility that cerebral po lyopia is due to recoding of visual receptive fields in primary visual cortex and that bilateral occipital lesions are a causative factor in the genesis of the disorder. (C) 1998 Elsevier Science Ltd. All right s reserved.