A Study of Rotation Test in Patients with unilateral Peripheral Vestibular Loss

Abstract

BACKGROUND: In general, it is well known that dizzy patients show a remarkable ability to compensate for the loss of peripheral vestubular function. When the patient had decreased response to caloric stimulation and showed no symptoms of vestibular dysfunction, we thought that was a compensated state of unilateral peripheral vestibular loss. OBJECTIVES: The purpose of this study is to provide the basic data for analysis of findings of further rotatory chair test through analyzing the results of rotation test of unilateral peripheral vestibular loss patients. MATERIALS AND METHODS: We analysed the findings of rotatory chair test and clinical manifestations of 24 cases of unilateral vestublar loss which didn't show any symptoms of vestibular dysfunction and they were confirmed by bithermal caloric test and Kobrak's ice water test. RESULTS: We could find that phase lead, low gain and asymmetry could persist despite of chronic compensated state and these findings were relatively common in patients with nonspecific vestibular symptoms. CONCLUSION: Abnornal phase lead and decreased gain were observed in the compensated unilateral vestibular loss patients who showed nonspecific symptoms including oscillopsia, vague unsteadiness. We thought that their compensation was not completely perfect and SHA test was a good tool which detect the minor degree of vestibular dysfunction. We have to consider the past history and nonspecific symptoms of patients through precise history taking. Frequency of SHA test is slower than that of normal human movement and this status is not a real physiologic condition, so it would be advisable to consider the results of other vestibular function tests for precise evaluation the degree of compensation, and the serial check is also recommended.