[Enhanced variability of the thermal test with patients with vestibular disease (author's transl)].

The reproducibility of nystagmus-intensity was measured with patients with peripheral vestibular disease, and with healthy persons, by a fivefold repetition of the same thermal stimulus. Variability of the data of the patients was considerably higher than of the healthy persons. Thus, the "normal" data have only a restricted value. Therefore, interpretation of thermal tests is more difficult for patients with an eventual vestibular disease. The origin of the enhanced variability seems to be the weakness of the reaction per se, because strong stimuli and hence strong reactions with healthy persons, have a lower relative standard deviation. Furthermore, tonic fluctuation in the diseased vestibular system is probable, as healthy ears of patients with unilateral vestibular disease show increased variability. An improvement of the method of the test is necessary. This can, for instance be achieved by an examination with eyes open under Frenzel's glasses and by repeated, by short and by strong stimuli.