General View of Vestibular Disorders

Abstract

The role of the labyrinthine receptors is to transduce the forces associated with head acceleration into a biological signal. Vestibular centres in the brain use this signal, in cooperation with visual and somatosensory signals, to detect the motion of the head and its position relative to gravity vector and to produce motor reflexes to maintain equilibrium and accurate vision during head movements. The evaluation of vestibular function is the mainstay of the general otoneurological examination and relies upon testing for static and dynamic imbalance in the vestibular system, positional testing, eye movement testing and testing for visual-vestibular interaction. The more recent aspects of two conditions, benign paroxysmal positional vertigo and ocular tilt reaction, are discussed. Their pathophysiological mechanisms are reinterpreted and re-evaluated on the basis of present knowledge of vestibulo-oculomotor function.

Key Words:

• vestihular system
• vestibular evaluation
• benign paroxysmal positional vertigo
• ocular tilt reaction