《英文msh詞典》Positional Nystagmus,Fatigable
[入口詞] Positional Nystagmus,Fatigable
[主題詞] Nystagmus,Pathologic
[英文釋義] Involuntary movements of the eye that are divided into two types,jerk and pendular. Jerk nystagmus has a slow phase in one direction followed by a corrective fast phase in the opposite direction,and is usually caused by central or peripheral vestibular dysfunction. Pendular nystagmus features oscillations that are of equal velocity in both directions and this condition is often associated with visual loss early in life. (Adams et al.,Principles of Neurology,6th ed,p272)