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Stroke of the right cerebral hemisphere often causes deficits in the judgement of the subjective visual vertical (SVV) and subjective tactile vertical (STV) which are related to central vestibular functioning. Clinically, deficits in the SVV/STV are linked to balance problems and poor functional outcome. Galvanic Vestibular Stimulation (GVS) is a non-invasive, save stimulation technique that induces polarity-specific changes in the cortical vestibular systems. Subliminal GVS induces imperceptible vestibular stimulation without unpleasant side effects. Here, we applied bipolar subliminal GVS over the mastoids (mean intensity: 0.7 mA, 20 min duration per session) to investigate its online-influence on constant errors, difference thresholds and range values in the SVV and STV. 24 patients with subacute, single, unilateral right hemisphere stroke were studied and assigned to two patient groups (impaired vs. normal in the SVV and STV) on the basis of cut-off scores from healthy controls. Both groups performed these tasks under three experimental conditions on three different days: a) sham GVS where electric current was applied only for 30s and then turned off, b) left-cathodal GVS and c) right-cathodal GVS, for a period of 20 min per session. Left-cathodal GVS, but not right-cathodal GVS significantly reduced all parameters in the SVV. Concerning STV GVS also reduced constant error and range numerically, though not significantly. These effects occurred selectively in the impaired patient group. In conclusion, we found that GVS rapidly influences poststroke verticality deficits in the visual and tactile modality, thus highlighting the importance of the vestibular system in the multimodal elaboration of the subjective vertical., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Unlabelled: Background Neglect is associated with disability, unawareness, poor long-term outcome, and dependence from caregivers. No randomized trial has evaluated the effects of smooth pursuit eye movement training (SPT) and visual scanning training (VST) at the bedside on these variables. Objective To compare the effects of SPT and VST in postacute stroke at 1 month with left neglect., Methods: We carried out an assessor-blinded, randomized controlled trial. The 24 participants were randomly allocated to either SPT or VST (n = 12 each). They received 20 treatment sessions lasting 30 minutes each at the bedside over 4 weeks. Outcome measures included the Functional Neglect Index (FNI) based on 4 tasks: find objects on a tray, stick bisection, picture search, and gaze orientation. In addition, the Unawareness and Behavioral Neglect Index (UBNI) with 6 items about unawareness and 4 about neglect in activities of daily living, the Help index (required assistance in 10 functional activities), the Barthel Index, and the rehabilitation phase were rated by treatment-blinded assessors. Outcome measures were obtained before and immediately after the end of the interventions and at a 2-week follow-up. Results Significantly greater improvements were obtained after SPT versus VST treatment in the FNI and UBNI, and there were continued improvements selectively in the SPT group 2 weeks later. Conclusions SPT accelerates recovery from functional neglect and reduces unawareness significantly. Bedside neglect treatment using SPT is effective and feasible early after stroke., (© The Author(s) 2013.)

Background: No treatment for auditory neglect and no randomized controlled trial evaluating smooth pursuit eye movement therapy (SPT) for multimodal neglect are available., Objective: To compare the effects of SPT and visual scanning therapy (VST) on auditory and visual neglect in chronic stroke patients with neglect., Methods: A randomized, prospective trial was conducted. Fifty patients with left auditory and visual neglect were randomly assigned. Twenty-four patients completed SPT therapy and 21 patients VST. Five patients (4 VST, 1 SPT) were lost. Each group received 1-hour sessions of neglect therapy for 5 consecutive days totaling 5 hours. Outcome measures in visual neglect (digit cancellation, visuoperceptual- and motor line bisection, paragraph reading) and auditory neglect (auditory midline) were assessed twice before therapy, thereafter, and at 2-week follow-up. The SPT group practiced smooth pursuit eye movements while tracking stimuli moving leftward. The VST group systematically scanned the same but static stimuli. Both groups were divided into subgroups, and effects were separately investigated for mild and severe neglect., Results: Both groups did not differ before therapy in clinical/demographic variables or neglect severity (auditory/visual). After treatment, the SPT group showed significant and lasting improvements in all visual measures and normal performance in the auditory midline. Neither visual nor auditory neglect impairments changed significantly after VST. Moreover, the treatment effect sizes (Cohen’s d) were considerably higher for visual and auditory neglect after SPT versus VST, both for mild and severe neglect., Conclusions: Repetitive contralesional, smooth pursuit training induces superior, multimodal therapeutic effects in mild and severe neglect.

Patients with homonymous hemianopia often show a contralesional shift towards their blind field when bisecting horizontal lines ('hemianopic line bisection error', HLBE). The reasons for this spatial bias are not well understood and debated. Eccentric fixation and adaptive orienting of eye movements towards the blind field have been suggested as hypothetical explanations but were not tested experimentally yet. Moreover, the role of spatial attention and visual search in the blind field are unsettled issues. Here, we tested in 20 stroke patients with chronic homonymous hemianopia (10 left-sided, 10 right-sided) without visual neglect, 10 healthy control subjects and 10 neurological control patients without hemianopia whether the HLBE is related to (a) eccentric fixation and (b) is influenced by spatial-attentional cueing (left, right) and (c) related to the degree of oculomotor compensation in the blind field. Perimetric mapping of the blind spot in the ipsilesional eye was performed in 39/40 subjects. Both hemianopic patient groups showed the typical HLBE towards their blind field, while the two control samples showed only a small but significant leftward shift known as pseudoneglect. The horizontal and vertical position of the blind spot in the ipsilesional eye was within normal limits in 38 out of 40 subjects, and did not differ significantly between the four samples. Moreover, the HLBE was not significantly correlated to the horizontal or vertical position of the centre of the blind spot, thus excluding eccentric fixation as an explanation for this spatial error. Furthermore, spatial cueing by manipulating the starting position of the bisection cue (left, right) did not affect the HLBE, arguing against attentional cueing effects well known from the line bisection error in patients with spatial neglect. Finally, the size of the saccadic search field in the scotoma was not significantly correlated to the HLBE in hemianopia. We conclude that eccentric fixation, contralesional hyperattention or ipsilesional hypoattention, or good or poor oculomotor compensation of the field loss itself are not likely causes of the HLBE in chronic homonymous hemianopia. Implications of these findings and alternative explanations are discussed., (Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.)

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., (Copyright © 2011 Elsevier Ltd. All rights reserved.)