The relationship between balance and visuospatial attention on hemispheric stroke survivors : a study of egocentric and allocentric neural processing

Abstract

Background: Impaired balance and visuospatial attention are well-documented sequelae of stroke. However, the interplay between balance function and visuospatial attention, particularly within egocentric and allocentric reference frames, remains poorly understood. Objective: This study aimed to elucidate the relationship between balance and visuospatial attention in stroke survivors with left- and right-hemisphere lesions and to investigate the underlying neural mechanisms. Methods: Seventeen patients with right-hemisphere stroke, sixteen with left-hemisphere stroke, and eighteen age-matched healthy controls participated in this study. Balance function was evaluated using Prokin, while visuospatial attention was assessed through tasks involving egocentric and allocentric reference frames. In addition, event-related potentials of the P1, N1, and P2 components were measured during the attention tasks. Results: Patients with left-hemisphere stroke exhibited superior balance and visuospatial attention performance compared to those with right-hemisphere stroke. Balance function was positively correlated with both egocentric and allocentric visuospatial attention performance in left-hemisphere stroke survivors. Attenuated P1 amplitudes and enhanced P2 amplitudes were observed during allocentric processing in right-hemisphere stroke survivors. The P2 amplitude at the O2 electrode was positively associated with medio-lateral velocity, ellipse area, and perimeter during balance tasks in left-hemisphere stroke survivors. Conclusions: Balance function is closely linked to selective attention and categorization processes in allocentric visuospatial tasks, particularly in patients with left-hemisphere stroke, suggesting that the right hemisphere may play an important role in mediating balance and visuospatial attention functions in the patients with mild to moderate stroke.