Disentangling vestibulo-ocular reflex cancellation and vestibulo-ocular reflex suppression in vestibular testing: definitions, mechanisms, and clinical applications

The terms “vestibulo-ocular reflex (VOR) cancellation” and “VOR suppression” are often used interchangeably in vestibular research and clinical testing, despite probing distinct computations. This review provides operational definitions that separate cancellation from suppression across common paradigms (visually enhanced VOR, VOR suppression, head-impulse paradigm/translational VOR, and suppression head-impulse paradigm/head-fixed target) by linking each task to the appropriate outcome measure (eye-in-head versus gaze-in-space) and to explicit timing windows (early approximately 0–150 msec reflex vs. later task-dependent modulation). Cancellation is framed as the goal to minimize eye-in-head motion when foveating a head-fixed target, whereas suppression reflects visually driven eye velocity (fixation/pursuit) that counteracts vestibular drive to stabilize gaze on a space-fixed target. We integrate vestibular-nuclear and vestibulo cerebellar mechanisms, including the influence of velocity storage, to explain frequency/velocity dependence and dissociations in peripheral vestibulopathies and central (cerebellar/brainstem) disorders. Finally, we propose a pragmatic reporting checklist and a decision algorithm to harmonize interpretation and to guide rehabilitation targets (adaptation, suppression training, substitution, and predictive cueing).