Article

Patients with right hemisphere lesions often show left spatial neglect and the
typical rightward deviation in horizontal line bisection. Previous studies have
shown that sensory stimulation modulates line bisection. A less well-known but
promising sensory stimulation method is galvanic vestibular stimulation (GVS).
This non-invasive technique leads to activation of the vestibular cortices and
adjacent cortical areas in the temporo-parietal cortex via polarization effects
of the vestibular nerves. This is accomplished by application of weak direct
currents, delivered by two electrodes attached to the mastoids. Despite the
relative benefits of GVS its effects on line bisection have not yet been studied
in neglect patients. Thus, the present study investigated the impact of GVS on
performance in a modified line bisection task in right-brain damaged patients
with versus without leftsided visual neglect. In neglect patients, but not in
control patients, left-cathodal and right-cathodal GVS significantly reduced the
rightward line bisection error as compared to Baseline (without GVS) and sham
stimulation. A larger decrease of the rightward line bisection error was observed
during right-cathodal GVS. Sham stimulation showed no specific effects on line
bisection. The beneficial effects of GVS might be due to activation of preserved
structures of the lesioned right posterior parietal cortex which is known to be
involved in line bisection.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS