Active Head Movement Analysis of Vestibulo-ocular Reflex Dynamics

Abstract The primary role of the vestibulo-ocular reflex (VOR) is to stabilize the eyes for clear vision throughout angular eye movements. Another alternative approach to VOR testing at higher frequencies is to use active head oscillations in which a rotational sensor attached to a head strap would monitor head movement. This method needs the use of a computer and other technology in its implementation. In this chapter, the use of active head oscillations for VOR testing is reviewed in laboratories. Previous research on active head movements are also presented in the chapter. These previous studies employed active head movements at frequencies both below and above 2 Hz with an earth-fixed visual target. Certain physiologic considerations in using active head movements in place of passive chair rotations are also clarified in this chapter. The methods, test protocol, and data acquisition and analysis in VOR testing are sequentially explained. Meniere's disease is also briefly discussed.