1991 Volume 1991 Issue Supplement51 Pages 26-30
When patients with vertigo are seen in the clinic, the presence or absence of spontaneous nystagmus is generally tested using Frenzel's glasses, and when spontaneous nystagmus is not found, a head-shaking test (HST) is conducted to detect spontaneous nystagmus. We recorded the ENG of these patients with eyes open in total darkness who showed no spontaneous nystagmus under Frenzel's glasses. In patients with no nystagmus under Frenzel's glasses, clear nystagmus was recognized with a maximum slow-phase velocity of 7.8°/sec and a minimum slow-phase velocity of 3.9°/sec. Therefore, in cases with a maximum slow-phase velocity of less than 7.8°/sec, the possibility that nystagmus may not be recognized with Frenzel's glass was indicated. Thus, ENG recording is useful and we use this as an index for treatment and follow-up studies.
