Nuti D, Vannucchi P, Pagnini P
Department of Otolaryngology, University of Siena, Italy.
J Vestib Res. 1996 May-Jun;6(3):173-84.
Benign paroxysmal positional vertigo of the horizontal semicircular canal (HC-BPPV) is a well-defined syndrome characterized by direction-changing horizontal positional nystagmus. We report the clinical features of 5 patients who illustrate the possible variables of the syndrome. In most cases, nystagmus is geotropic and more intense when the pathological ear is lowermost; less often the syndrome presents with apogeotropic nystagmus that is more intense when the affected ear is uppermost. The nystagmus pattern may vary in time in the same patient, changing from apogeotropic to geotropic even in observations at short intervals. In some patients, the features indicate involvement of more than one canal, either simultaneously or in succession. It is sustained that the clinical findings can be explained by movement of endolymph caused by displacement of otoconia in the semicircular canals and that variants are due to different positions of the otoconia within the canals.
水平半规管良性阵发性位置性眩晕（HC - BPPV）是一种明确的综合征，其特征为方向改变的水平位置性眼球震颤。我们报告了5例患者的临床特征，这些特征说明了该综合征可能存在的变量。在大多数情况下，眼球震颤是向地性的，当患耳处于最低位置时更为强烈；较少见的情况是，该综合征表现为背地性眼球震颤，当患耳处于最高位置时更为强烈。在同一患者中，眼球震颤模式可能随时间变化，即使在短时间观察内也可能从背地性变为向地性。在一些患者中，特征表明不止一个半规管受累，可能是同时受累或相继受累。一般认为，临床发现可以通过半规管内耳石移位引起的内淋巴运动来解释，而变异则是由于耳石在半规管内的不同位置所致。
