Galvanic Pseudonystagmus: Electronystagmographically recorded Nystagmus-like Reaction induced by Galvanic Action

Abstract

On the basis of clinical ENG using bipolar galvanic stimulation (binauri-cular or monoauricular) the traced curves allow a distinct differentiation between a long and a short phase in the reaction at BB as well as at BM. The direction of the short phase altered according to the position of the cathode. It is clearly apparent also that the regular rhythm is synchronous with the cardiac rhythm in the simultaneously recorded cardiogram, only delayed in phase.

Concurrent nieasurenients of the decrease in voltage between the lead off electrodes during stimulation showed that the interference voltage is, on average, 850 (1100-600) times higher than the recorded voltage variations. It is also apparent that the nionoauricular stiniulation predoniinantly affects only the stimulated side. On the basis of the literature and the curves submitted in the present paper it must be concluded that direct ENG is not applicable as a recording method in the galvanic test, as the tracings merely represent resistance variations between the lead-off electrodes synchronous with the heart beat.