Abstract
Since only a small number clinics are capable of recording ENG on the first visit of patients with vertigo and/or equilibrium disturbance, we studied the relationship between the changes of spontaneous nystagmus in ENG and the number of days from the first visit to the day recording was done. In the first report, we found that there was no relation between the incidence of nystagmus and the number of days until the date of recording within two weeks from the first visit. However, this result represented only the qualitative nature of nystagmus in ENG. In order to clarify this relationship more precisely, quantitative analysis became necessary. In the present study, we analyzed the relationship between the frequency and the slow-phase velocity of nystagmus and the number of days until recording. ENGs were recorded in 1, 260 patients with vertigo and/or disequilibrium and were analyzed. We found a close relationship between the frequency as well as the slow phase of nystagmus and the number of days from the first visit, namely, the frequency and the slow phase of nystagmus significantly decreased with days past. We conclude that the present status of ENG recording in most clinics is insufficient. ENG recording should be carried out as early as possible.
