A modified method of electronystagmography for recording eye movement during the galvanic vestibular test

This study demonstrates a new technique for recording galvanic nystagmus using conventional electrooculography: a first pair of electrodes is placed at the nasal and lateral orbital margin of the left eye. An additional pair of electrodes is placed near the left angle of the mouth. This latter pair of electrodes picks up voltage variations induced by heart beat but only a minimal part of voltage variations caused by eye movements during bipolar, binaural electric stimulation. Electronic subtraction of the voltage variations near the angle of the mouth from the voltage variations at the equilateral eye cancels the cardiac interference and allows a pure recording of horizontal eye movements. 35 of 40 subjects could be examined successfully.