STUDIES ON CALORIC TEST FOR THE PURPOSE OF THE DIAGNOSIS OF VESTIBULAR LESIONS

Abstract

Clinical studies on vestibular function test, particularly on caloric test were described. A brief review was given of the results of these examinations in normal subjects. Z-test, a new method of caloric test, devised by Ino, and caloric pattern test developed from the Z-test (Ino, Okamoto) were described.Observations on a servies of 30 cases of Meniere's disease as peripheral vestibular disorders and of 32 cases of central vestibular disorders including brain tumor were presented. Results Obtained from the exsminations of spontaneous nystagmus and positional nystagmus, with observations by rotation test, alternated hot or cold test, Z-test and Caloric pattern test were as follows.1.Spontaneous nystagmus gave no diagnostic indication. 2.Positional nystagmus:In about 50, 0 of cases of Meniere's disease direction fixed positional nystagmus were presented, and this is considered desirable to put into practice as a routine test of vestibular function. 3.Ashibumi-test:In many cases of Meniere's disease, the deviating side was commonly dire- cted to the slow phase of nystagmus. 4.Rotation test:Vestibular asymmetry was observed infrequently in this method.For this reason, this test is considered to give no indication of the localization of lesions. 5.Alternated hot or cold test:The findings of directional preponderance (D.P.) and canal paresis (C.P.) presented no indication of whether lesions were located in central or peripheral. 6.Z-test:Investigation of the latent period seemed to direct to the localization of lesions. 7.Caloric pattern test:Type 2 examined by this method showed the characteristic features of peripheral vestibular disorders, and it might be thought as a vestibular recruitment phenomenon. In many cases of central vestibular disorders were often found.Type 3, or Type 4.This sugge- sted that they are regarded as an expression of central checking mechanism.In Meniere's disease, Type 1 or Type 2 were frequently found.Type 1 usually showed D.P., and C.P.was oftentimes found in Type 2.This suggests that C.P.is regarded as a sign of cupular affection and D.P.is regarded as that of utricular disorders