See-saw nystagmusの1症例

A Case of Nasal Encephalocele with See-saw Nystagmus

　緒言

　See-saw nystagmusとはあたかもシーソー様に両眼球が互に逆方向の垂直運動を繰り返す異常眼球運動であり，回旋要素を含む。その成因病巣部位については充分解明されてはいない。われわれは，頭部外傷の16年後にsec-saw nystagmusを伴う鼻腔内脳瘤症例を報告し，眼球運動の成因についての若干の知見を加えた。

A 36-year-old Japanese male presented with a well defined bitemporal hemianopia, and nasal encephalocele with see-saw nystagmus. The see-saw nystagmus of this patient was characterized by vertical opposed pendular eye movement, associated with torsion of the eyes. The one eye moved up extorsionally and the other eye moved down in-torsionally. The nystagmus was analysed by using a video-tape recorder and an electronystagmo-graphy. It was assumed that this see-saw nystag-mus was caused by a parasellar lesion.