Visual perceptual deficits and their contribution to walking dysfunction in individuals with post-stroke visual neglect.

BACKGROUND

Unilateral spatial neglect (USN), a highly prevalent and disabling post-stroke deficit, severely affects functional mobility. Visual perceptual abilities (VPAs) are essential in activities involving mobility. However, whether and to what extent post-stroke USN affects VPAs and how they contribute to mobility impairments remains unclear.

OBJECTIVES

To estimate the extent to which VPAs in left and right visual hemispaces are (1) affected in post-stroke USN; and (2) contribute to goal-directed locomotion.

METHODS

Individuals with (USN+,  = 15) and without (USN-,  = 15) post-stroke USN and healthy controls (HC,  = 15) completed (1) psychophysical evaluation of contrast sensitivity, optic flow direction and coherence, and shape discrimination; and (2) goal-directed locomotion tasks.

RESULTS

Higher discrimination thresholds were found for all VPAs in the USN+ group compared to USN- and HC groups (< 0.05). Psychophysical tests showed high sensitivity in detecting deficits in individuals with a history of USN or with no USN on traditional assessments, and were found to be significantly correlated with goal-directed locomotor impairments.

CONCLUSION

Deficits in VPAs may account for the functional difficulties experienced by individuals with post-stroke USN. Psychophysical tests used in the present study offer important advantages and can be implemented to enhance USN diagnostics and rehabilitation.