Evaluation of Ewald's Second Law. An Electronystagmographic Study

Abstract

To evaluate Ewald's second law forty normal young adults had caloric tests performed in both supine and prone position. Electronystagmo-graphy was used. The values of nystagmus show individual variation, these being more marked in total beats and total amplitude. The direction of nystagmus has a definite relationship with the direction of the endolymph flow. There is no difference in the right and left ears in our study. Intensity of nystagmus shows a higher response to cold stimulation. The responses in the prone position are much less than in the supine position. The total ampullofugal responses show no significant difference from those of total ampullopetal responses, thus contradicting Ewald's second law in man.