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

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.