Background: Patients with right hemisphere damage are often unaware of, inattentive to and fail to interact with stimuli on their left side. This disorder, called hemispatial neglect, is a major source of disability. Inducing leftward ocular pursuit by optokinetic stimulation (OKS) relieves some of the signs of unilateral neglect. However, it is difficult to provide patients with a continuously moving background that is required for OKS. We studied whether OKS projected onto a see-through head-mounted display (HMD) would help treat neglect.
Methods: 14 patients with neglect after cerebral infarction performed line bisections on a computer screen, both with and without OKS that was either delivered by the HMD or on the same screen that was displaying the lines that were to be bisected.
Results: The line bisection performances were significantly different in the four conditions (P < 0.001). The post hoc analyses indicated that the rightward deviation observed in the control conditions on the line bisection tasks without OKS, improved significantly with the use OKS in both the HMD and screen conditions (α < 0.05). The results between the screen and HMD conditions were also different (α < 0.05). The OKS in the HMD condition corrected patients' rightward deviation more toward the actual midline than did the OKS provided during the screen condition.
Conclusions: OKS projected onto the see-through HMD improved hemispatial neglect. The development of a portable device may aid in the treatment of neglect.