Post-stroke visual neglect affects goal-directed locomotion in different perceptuo-cognitive conditions and on a wide visual spectrum

Abstract

Background: Unilateral spatial neglect (USN), a highly prevalent and disabling post-stroke deficit, has been shown to affect the recovery of locomotion. However, our current understanding of USN role in goal-directed locomotion control, and this, in different cognitive/perceptual conditions tapping into daily life demands, is limited.

Objectives: To examine goal-directed locomotion abilities in individuals with and without post-stroke USN vs. healthy controls.

Methods: Participants (n = 45, n = 15 per group) performed goal-directed locomotion trials to actual, remembered and shifting targets located 7 m away at 0° and 15° right/left while immersed in a 3-D virtual environment.

Results: Greater end-point mediolateral displacement and heading errors (end-point accuracy measures) were found for the actual and the remembered left and right targets among those with post-stroke USN compared to the two other groups (p < 0.05). A delayed onset of reorientation to the left and right shifting targets was also observed in USN+ participants vs. the other two groups (p < 0.05). Results on clinical near space USN assessment and walking speed explained only a third of the variance in goal-directed walking performance.

Conclusion: Post-stroke USN was found to affect goal-directed locomotion in different perceptuo-cognitive conditions, both to contralesional and ipsilesional targets, demonstrating the presence of lateralized and non-lateralized deficits. Beyond neglect severity and walking capacity, other factors related to attention, executive functioning and higher-order visual perceptual abilities (e.g. optic flow perception) may account for the goal-directed walking deficits observed in post-stroke USN+. Goal-directed locomotion can be explored in the design of future VR-based evaluation and training tools for USN to improve the currently used conventional methods.

Keywords: Cerebrovascular accident; gait; hemineglect; locomotion; trajectory deviation.