Improvement of visual scanning after DC brain polarization of parietal cortex in stroke patients with spatial neglect

Previous studies have demonstrated that transcranial direct current (DC) brain polarization can modulate cortical excitability in the human brain. We investigated the effect of anodal DC brain polarization of right parietal cortex on visuospatial scanning in subacute stroke patients with spatial neglect. The patients underwent two neglect tests – figure cancellation and line bisection – before and immediately after anodal DC or sham in a double-blind protocol. Anodal DC was applied to the scalp over the right posterior parietal cortex (PPC) with an intensity of 2.0 mA for 20 min. Anodal DC brain polarization, but not sham, led to significant improvement in the both neglect tests. These results document a beneficial effect of DC brain polarization on neglect.