在一个特定头位或由一个头位变换到另一个头位时产生的眩晕称之为位置性眩晕;在此同时伴随出现的眼震称之为位置性眼震(以下简称PN)。PN的出现不一定伴有眩晕。 [原因]检查时只在一个或二个头位出现眼震的原因目前尚难理解。Fernandez等(1959)报导将动物双侧迷路切除后无PN发生。因此,PN的发生至少要具备一侧具有活动能力的周围前庭器官。对地心吸力来说,新头位的定位信号来自中枢。在某些情况下(如前庭功能或小脑功能部分缺损)就会出现PN。由于良性阵发性位置性眼震(以下简称BPPN) Dizziness caused when a specific head position or a head position is changed to another head position is called positional vertigo; at the same time, the nystagmus that accompanies it is called a positional nystagmus (hereinafter referred to as PN). The appearance of PN is not necessarily accompanied by dizziness. [Cause] The cause of nystagmus at examination of only one or two head positions is hard to understand. Fernandez et al. (1959) reported that PN disappeared after bilateral excision of the animal. Therefore, the occurrence of PN should have at least one side of the activity of the surrounding vestibular organs. For geospatial absorption, the new head position signal comes from the center. In some cases (such as vestibular function or cerebellar function defects) will appear PN. Due to benign paroxysmal positional nystagmus (hereinafter referred to as BPPN)