Department of Neurology, Royal Prince Alfred Hospital, Sydney, NSW.
Med J Aust. 2011 Nov 7;195(9):518-22. doi: 10.5694/mja11.11001.
Benign positional vertigo (BPV) is the most common cause of episodic vertigo. It results from activation of semicircular canal receptors by the movement of calcium carbonate particles (otoconia) which dislodge from the otolith membranes. During changes in head position, the otoconia either float freely within the semicircular canal duct (canalithiasis) or adhere to and move with the cupula of the canal (cupulolithiasis). BPV from canalithiasis evokes brief spells of vertigo lasting seconds and can be diagnosed at the bedside by provoking paroxysmal vertigo and nystagmus on tilting the head in the plane of the affected canal. The nystagmus has a unique rotational axis perpendicular to the affected canal. The Dix-Hallpike test is a simple means of confirming the diagnosis in patients presenting with episodic vertigo or imbalance. Audiovestibular tests are only indicated if a symptomatic primary underlying inner ear disease is suspected. In over 80% of patients, BPV can be treated successfully with a single bedside Epley (particle-repositioning) manoeuvre, which can be performed by any medical practitioner.
良性阵发性位置性眩晕（BPV）是阵发性眩晕最常见的原因。它是由碳酸钙颗粒（耳石）从耳石膜上脱落，使半规管受体激活引起的。当头位改变时，耳石要么在半规管管腔内自由漂浮（耳石症），要么附着并随管腔的帽状结构一起移动（壶腹嵴结石症）。由耳石症引起的 BPV 会引发短暂的眩晕发作，持续数秒，可以通过在受累半规管平面倾斜头部来诱发阵发性眩晕和眼球震颤，在床边诊断。眼球震颤具有与受累半规管垂直的独特旋转轴。Dix-Hallpike 试验是一种简单的方法，可用于确认出现阵发性眩晕或失衡的患者的诊断。如果怀疑有症状的原发性内耳疾病，仅需进行听觉前庭测试。在超过 80%的患者中，单次床边 Epley（颗粒复位）手法治疗即可成功治疗 BPV，任何医务人员都可以进行该操作。
