Periodic Alternating Nystagmus.

Lee, Dong Ho; Hong, Sung Bum; Lee, Jong Bok

Original Article

Journal of the Korean Ophthalmological Society 1993;34(2):159-163.
Published online February 1, 1993.

Periodic Alternating Nystagmus.

Dong Ho Lee, Sung Bum Hong, Jong Bok Lee

Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.

중립상 ( Neutral phase ) 이 주기적으로 변하는 유아안진

이동호(Dong Ho Lee),홍성범(Sung Bum Hong),이종복(Jong Bok Lee)

Abstract

Periodic alternating nystagmus is a horizontal jerk nystagmus that periodically changes in amplitude and directions every 3 or 4 minutes. Usually the eyes beat in one direction for approximately 90 seconds and then go into a null phase for 10 to 20 seconds before beginning to move in the opposite direction and continued about 90 seconds. The exact mechanism is unknown but the rhythmic alteration of the null zone of horizontal jerk nystagmus is taken as a possible mechanism. These patients periodically show alternating head turning. The authors report 6 cases of congenital periodic alternating nystagmus which show horizontal jerk nystagmus of rhythmic direction change and confirmed by electro-oculogram.

Key Words: Electro-oculogram;Horizontal jerk nystagmus;Periodic alternating nystagmus