抄録
We examined postrotatory nystagmus in 43 patients with vertigo. The slow phase of postrotatory nystagmus was analyzed by a second order system represented by the following equation.
y (t) =A (e-t/T2-et/T1) /T2-T1
y (t) =slow phase of postrotatory nystagmus (°/sec).
T1=short time constant of system of postrotatory nystagmus (sec).
T2=long time constant of system of postrotatory nystagmus (sec).
Calculation was done by the most-least square method and values A, T1, T2 were determined.
The values of 15 healthy subjects without any ear or brain disease were used to determine the normal range.
In 43 patients with vertigo the short time constant had no relation to the attacks of vertigo; however, the long time constant was shortened in parallel with the degree of vertigo.
Ampllopetal flow in the affected ear, especially during vertigo, showed a shorter than normal long-time constant.
We conclude that patients with vertigo have a shorter long-time constant and a low AP value. This means that patients with vertigo are intolerate of longer stimuli.
