Rotational Chair Testing
The rotational chair is the "gold standard" for quantifying bilateral vestibular system weakness and independent utricle function. It allows the audiologist to thoroughly assess vestibular compensation. The rotational chair also enables him/her to identify central vestibular system disorders in the presence of a normal caloric testing, and, when used in conjunction with the VEMP, allows an entire assessment of the otolith system. This is also the vestibular examination of choice for children, since they find it more tolerable than caloric testing.
The rotational chair also examines each utricle independently via otolith sub testing. The otolith system consists of the utricles and saccules, which are the sensory organs in the inner ear that convert linear acceleration into an electrical code the brain can use. The utricle is responsible for sensing horizontal acceleration. Following stimulation of one of the utricles, the patient perceives that the environment is tilting. This is assessed utilizing Unilateral Centrifugation (UC) and Off Axis Vertical Rotation (OVAR) testing.