Unilateral stroke

Funding Information: This work was supported by Oskar ?flunds Stiftelse sr.; the University Hospital of Helsinki, Finland; and Alfred Kordelin Foundation. We thank Jari Lipsanen for statistical consultancy and Esko Ruuskanen for assistance in the raw data analysis, Viljami Salmela for consultations on visual perception, Kimmo Alho for commenting the manuscript, and Daniel Villarreal for assistance in proofreading the manuscript, our colleagues who assisted in the recruitment of their patients to the study, and the participants who generously gave their time to take part in this research. Publisher Copyright: Copyright © INS. Published by Cambridge University Press, 2021.Objective: Patients with unilateral stroke commonly show hemispatial neglect or milder contralesional visuoattentive deficits, but spatially non-lateralized visuoattentive deficits have also been reported. The aim of the present study was to compare spatially lateralized (i.e., contralesional) and non-lateralized (i.e., general) visuoattentive deficits in left and right hemisphere stroke patients. Method: Participants included 40 patients with chronic unilateral stroke in either the left hemisphere (LH group, n = 20) or the right hemisphere (RH group, n = 20) and 20 healthy controls. To assess the contralesional deficits, we used a traditional paper-and-pencil cancellation task (the Bells Test) and a Lateralized Targets Computer Task. To assess the non-lateralized deficits, we developed a novel large-screen (173 × 277 cm) computer method, the Ball Rain task, with moving visual stimuli and fast-paced requirements for selective attention. Results: There were no contralesional visuoattentive deficits according to the cancellation task. However, in the Lateralized Targets Computer Task, RH patients missed significantly more left-sided than right-sided targets in bilateral trials. This omission distribution differed significantly from those of the controls and LH patients. In the assessment of non-lateralized attention, RH and LH patients missed significantly more Ball Rain targets than controls in both the left and right hemifields. Conclusions: Computer-based assessment sensitively reveals various aspects of visuoattentive deficits in unilateral stroke. Patients with either right or left hemisphere stroke demonstrate non-lateralized visual inattention. In right hemisphere stroke, these symptoms can be accompanied by subtle contralesional visuoattentive deficits that have remained unnoticed in cancellation task.Peer reviewe