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  • Hena Ahmad
    Imperial College London
  • Qadeer Arshad
    Imperial College London
  • Yuilya Nigmatullina
    Imperial College London
  • Mitesh Patel
    Imperial College London
  • Adolfo M Bronstein
    Imperial College LondonImperial College Healthcare NHS Trust
  • Ed Roberts
    Imperial College London
Functional imaging, lesion studies and behavioural observations suggest that vestibular processing is lateralised to the non-dominant hemisphere. Moreover, disruption of interhemispheric balance via inhibition of left parietal cortex using transcranial direct current stimulation (tDCS) has been associated with an asymmetric suppression of the vestibulo-ocular reflex (VOR). However, the mechanism by which the VOR was modulated remains unknown. In this paper we review the literature on non-invasive brain stimulation techniques which have been used to probe vestibular function over the last decade. In addition, we investigate the mechanisms whereby tDCS may modulate VOR, e.g. by acting upon pursuit, VOR suppression mechanisms or direct VOR modulation. We applied bi-hemispheric parietal tDCS in 11 healthy subjects and only observed significant effects on VOR gain (tdcs * condition p=0.041) – namely a trend for VOR gain increase with right anodal/left cathodal stimulation, and a decrease with right cathodal/left anodal stimulation. Hence, we suggest that the modulation of the VOR observed both here and in previous reports, is directly caused by top-down cortical control of the VOR as a result of disruption to interhemispheric balance, likely parietal.
Original languageEnglish
JournalJournal of Vestibular Research
Volume24
Issue number5/6
Publication statusPublished - 17 Dec 2014
Externally publishedYes
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