The Acute Effects of Unilateral Vestibular Neurectomy on Sensory and Motor Tests of Human Otolithic Function

Abstract

Patients were tested 1 day before and 1 week after therapeutic unilateral vestibular neurectomy (UVN) on vestibular tests which are likely determined primarily by otolithic function. UVN causes a maintained ocular torsion: fundus photographs showed that both eyes of every patient were rolled such that the upper pole of both eyes was tonically deviated towards the operated side, and there is a corresponding change in the perceived gravitational horizontal: patients set a small bar of LEDs bar down on the same side as their operation. One week after UVN, patients showed an asymmetrical sensitivity to linear acceleration vectors directed along their interaural axis in comparison to their preoperative settings for the same stimuli.

Key Words:

• otolith
• torsion
• oculomotor
• vestibular
• vestibular compensation
• ocular counterrolling
• labyrinthectomy