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Authors & Affiliations
Liliane Borel, Arnaud Saj, Jacques Honoré
Abstract
Introduction. Studies of peripheral vestibular loss indicate that its consequences may vary depending on the impaired side. For instance, a left-sided loss tends to have a greater impact on the representation of body orientation. Our hypothesis here was that the influence on balance also depends on the side of the lesion.Methods: Balance was examined in 21 patients with cochleovestibular nerve schwannoma (13 on the left side, 8 on the right side) one day before and two months after neurotomy. We measured the velocity of the center of foot pressure displacements and the signal power density in both static and dynamic conditions and under three visual conditions of increasing difficulty: eyes open, eyes closed, and optokinetic stimulation (Multitest®, Framiral).Results. In static conditions, the velocity increased with the difficulty of the postural task, and this increase was more pronounced in patients with left-side than with right-side loss. Additionally, the signal power was higher in the case of left-side loss. In dynamic conditions, the high frequency of falls prevented a similar analysis. However, it is worth noting that two months after neurotomy, the frequency of falls was higher in the case of left-side loss.Discussion. In the chronic stage, postural balance was more impaired after left unilateral vestibular loss compared to right-side loss. The differences became more prominent as the difficulty of the postural context increased, i.e., when the cognitive cost of balance was higher. Interestingly, these postural findings are consistent with those observed in the study of body representations.