Article

Optokinetic stimulation (OKS) modulates many facets of the neglect syndrome. This
sensory stimulation technique is known to activate multiple brain regions
(temporo-parietal cortex, basal ganglia, brain stem, cerebellum) some of which
are involved in auditory and visual space coding. Here, we evaluated whether OKS
modulates auditory neglect transiently and induces a sustained effect (Study 1),
and whether repetitive OKS permanently recovers auditory neglect (Study 2). In
Study 1, 20 patients with visuospatial neglect and auditory neglect in an
auditory midline task following rightsided stroke were randomly allocated to an
experimental and a control group matched for neglect severity and
socio-demographic factors. Both groups showed a stable, pathological shift of
their auditory subjective median plane (ASMP) in front space to the right side.
During leftward OKS the experimental group showed a complete normalization of the
shift of the ASMP, which endured until 30 min poststimulation, and returned
almost to baseline values 24h after OKS. In contrast, the control group who
viewed the identical but static dot pattern, showed neither change in their ASMP
during this condition, nor any significant change at 30 min or 24h
poststimulation. In Study 2, we show in two samples of neglect patients (N = 3
each) that repetitive leftward OKS with smooth pursuit eye movements as a therapy
induces lasting improvements in auditory (the ASMP) and visual neglect while
visual scanning therapy yielded no measurable effects on auditory and
significantly smaller effects on visual neglect. In conclusion, the experiments
show that a single session of OKS induces rapid though transient recovery from
auditory neglect including a sustained effect after termination of stimulation,
while repetitive OKS therapy yields enduring and multimodal recovery from
auditory and visual neglect. OKS therapy with pursuit eye movements therefore
represents a multimodally effective and easily applicable technique for the
treatment of auditory and visual neglect.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS