Compensatory saccades differ between those with vestibular hypofunction and multiple sclerosis pointing to unique roles for peripheral and central vestibular inputs

Abstract

Compensatory saccades (CSs) are recruited by individuals with unilateral vestibular deafferentation (UVD) to compensate for an impaired vestibulo-ocular reflex (VOR). The effectiveness of CS in multiple sclerosis (MS), a central vestibular impairment, is unknown. We show that in UVD and in MS, covert CSs compensate for reduced VOR gain and minimize gaze position error (GPE), yet in >50% of individuals with MS, overt CS worsened GPE, suggesting unique roles for peripheral and central vestibular inputs.