Reduction of visuo-spatial neglect with vestibular galvanic stimulation.

The purpose of the present investigation was to determine the effect of galvanic vestibular stimulation on visuo-spatial neglect without inducing nystagmus and associated discomfort. Fourteen patients with right-hemisphere stroke with neglect were assessed with two visuo-motor tasks ("Line crossing" and "Star cancellation") on three occasions. Seven of the subjects received galvanic vestibular stimulation during the second condition (Experiment 1), whereas the other seven received stimulation during the third assessment (Experiment 2). Between-group comparisons of stimulation effects were performed by analyzing change on visuo-spatial neglect from the first to the second condition in the two experimental groups. A significantly larger effect was demonstrated on the "Line crossing" task in Experiment 1. This finding suggests a stimulation effect beyond practice/spontaneous recovery, and may provide new possibilities in rehabilitation research because the stimulation can be given without discomfort.