Quantitative assessment of the electronystagmogram of the eye-tracking test (eye-tracking pattern) was undertaken in 20 normal subjects and 70 patients with vertigo. The abnormal recordings, contrary to the normal, showed, in varying degrees, remarkable irregularities of eye speed. These irregularities appeared in the form of spikes on the electronystagmogram at the time constant of 0.03 second. We measured the height of the spikes using 40°/sec as a unit and added the units of spikes appearing during a nine-second period to obtain the total index. Total indices ranged from zero (normal) to 40 + (severely abnormal), and their values showed levels of abnormality in the eye-tracking pattern more accurately than the visual analysis in current use.
