Unilateral Stroke: Computer-based Assessment Uncovers Non-Lateralized and Contralesional Visuoattentive Deficits

Abstract

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.

Computer-Based Assessment: Dual-Task Outperforms Large-Screen Cancellation Task in Detecting Contralesional Omissions

“…As previously described (Villarreal et al, 2020(Villarreal et al, , 2021, LH patients in our sample showed no spatial bias in visual attention, and RH patients showed only subtle neglect, which was not evident in the traditional cancellation task, the Bells Test. Therefore, in the present study, we used more sophisticated approaches for data analysis to potentially increase the sensitivity of the new cancellation task.…”

“…As the RH patients' visuospatial attention deficits were only subtle, they became more clearly evident in bilateral than unilateral trials, i.e., as an extinction. While the phenomenon was seen here in the dual-tasks, RH patients also showed extinction in the single task in our previous study (Villarreal et al, 2021). Our first study (Villarreal et al, 2020) demonstrated that the RH patients (but not LH patients) showed statistically reliable contralesional omissions for unilateral targets as well, in two different dual-tasks.…”

“…The phenomenon may be explained by general inattention, which commonly co-occurs with neglect (Hjaltason et al, 1996;Husain and Rorden, 2003). In fact, our previous study (Villarreal et al, 2021) explicitly demonstrated that the RH patients were suffering from general inattention. LH group was suffering from general visual inattention as well but did not show neglect or extinction (Villarreal et al, 2020(Villarreal et al, , 2021.…”

“…In fact, our previous study (Villarreal et al, 2021) explicitly demonstrated that the RH patients were suffering from general inattention. LH group was suffering from general visual inattention as well but did not show neglect or extinction (Villarreal et al, 2020(Villarreal et al, , 2021. Therefore, it is likely that RH group's statistically reliable contralesional omissions are due to some specific consequence of right hemisphere damage.…”

Virtual reality tasks with eye tracking for mild spatial neglect assessment: a pilot study with acute stroke patients

“…Instead, USN+ patients’ total score was significantly lower than the controls’ in the multiple task variant, showing both lateralized and non-lateralized attention deficits. General inattention has been shown to co-occur with USN ( Ting et al, 2011 , Nurmi et al, 2018 , Villarreal et al, 2021 ). The difference between the score results in single and multiple tasks may also partly relate to the practice effect: a single task was always performed before multiple task.…”