Vestibular Testing-Rotary Chair and Dynamic Visual Acuity Tests.

The human vestibular system is exquisitely sensitive to detect linear and rotational head acceleration signals, processed in the brainstem and subsequently relayed to the extraocular motor neurons to generate a compensatory eye rotation. This vestibulo-ocular reflex (VOR) ensures clear and stable vision during head rotation, enabling humans to keep gaze on their desired target. In this chapter, we describe the rotary chair - one physiologic measure of the VOR, and the dynamic visual acuity (DVA) test - one behavioral measure of the VOR. Advances in the use of each measure are covered and include establishing normative values, expanding into non-vestibular diagnoses, and broadening the application of each measure. These recent advances in rotary chair and DVA test methods help in extending our knowledge of this 3-dimensional motion sensor.