交代性眼振3症例

NYSTAGMUS ALTERNANS

　Ⅰ．緒言

　開眼正中位で眼振方向が周期的に交代する自発性眼振の報告は1920年のBorriesにはじまり，以来今日迄に26例の報告がなされているが，本邦においては勝見（1960），川畑（1960）による2症例を見るのみである。

　我々は昭和37年7月から同年11月に至る比較的短期間に交代性眼振と診断された3症例を経験し，Electronystagmographieによる詳細な観察を行つたのでここに報告する。

Three cases of nystagmus alternans are studied with electronystagmography. The fol-lowing characteristics of nystagmus alternans are recorded. 1) A spontaneous nystagmus which is elicited with open eyes with the vision fixed directly in front and that chan-ges its direction alternatingly periodically can be changed to the direction of the eye-ball fixation when the eyes are closed and fixed at a certain direction.

2) With stimulation of the vestibule the spontaneous nystagmus will change its character by losing the alternating effect.

3) Among the patients who are affected with nystagmus alternans there are some who cannot be induced to show optokinetic nystagmus.

4) There are a number of variations in nys-tagmus alternans; it could be further divi-ded into various classification.