[Central nervous system influences on vestibulo-ocular and vestibulospinal functions exemplified by hand dominance]

The influence of the hand dominance and the hemispheric dominance on vestibulo-ocular and vestibulo-spinal responses was investigated. 40 healthy voluntary soldiers between 18 and 22 years old who were known to be left handed were examined. A special psychomotoric test was performed for quantification of the hand dominance. Spontaneous nystagmus, vestibulo-ocular reflex after caloric and pendular stimulation, vestibulo-spinal tests and pure-tone audiogram were recorded. Directional preponderance to the left side was observed in most of the left handed subjects. Spontaneous nystagmus was directed to the left in subjects with extreme left hand dominance. There were no side differences in the caloric test nor in the pendular tests. Orientation in the Unterberger's stepping test was up to 200 degrees to the left. With increasing left handed dominance the intensity of directional preponderance, spontaneous nystagmus and body rotation to the left side also increased. Variation of the normal VOR and vestibulo-spinal responses due to central nervous influences is obvious. Directional preponderance and vestibulo-spinal responses should therefore be carefully estimated in clinical diagnosis.