Torsional eye movement responses to monaural and binaural galvanic vestibular stimulation: side-to-side asymmetries.
Vestibular stimulation by head accelerations always involves multisensory activation of the vestibular, somatosensory, and visual systems. Over the past few years, galvanic vestibular stimulation (GVS) has become increasingly popular for testing vestibular function for clinical and research purposes. Although GVS provides a nonphysiological stimulation, it is more selective than natural head accelerations and is thus an attractive tool for such tests. Eye movement responses elicited by GVS mainly consist of torsional and horizontal components, as first described by Hitzig in 1871. Animal experiments have shown that GVS increases the vestibular afferent spike frequency at the cathodal site and decreases it at the anodal site of stimulation. As a continuation of a study on age-dependency of eye movement responses to GVS, we analyzed side-to-side asymmetries in healthy subjects. It is necessary to know the normal range of asymmetry between left- and right-sided stimulation to interpret GVS responses in patients with vestibular diseases.
Jahn
Klaus
K
Department of Neurology, Klinikum Grosshadern, Ludwig-Maximilians University, Munich, Germany. klaus.jahn@lrz.uni-muenchen.de
Naessl
Andrea
A
Strupp
Michael
M
Schneider
Erich
E
Brandt
Thomas
T
Dieterich
Marianne
M
D000328:Adult; D000375:Aging / Q000502:physiology*; D004558:Electric Stimulation; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D019416:Head Movements / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009475:Neurons, Afferent / Q000502:physiology; D009760:Nystagmus, Physiologic / Q000502:physiology*; D014722:Vestibule, Labyrinth / Q000502:physiology*